Video and Audio Evidence In Court: How to Prevail In Civil and Criminal Cases by Properly Utilizing Audio, Video, and Still Image Evidence

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I was so frustrated seeing attorneys make the same mistakes that I had to prepare this class.

It got embarrassing.  During opening statements, the opposing attorney made a claim about the video evidence that was out of the blue and, although Tony couldn’t put his finger on it, seemed to bemisleading.

Tony was unprepared, and the opposing attorney took advantage. He misrepresented video evidence in open court, and Tony didn’t have the tools to object because he didn’t spend the time to understand specifics of his evidence.

Forensic Line Please Cross, sometimes attorneys resist careful analysis because it seems "the evidence is the evidence"

NCAVF welcomes attorneys to visit our offices with their video, audio, and still image evidence and to work with us in person.

Ever had this happen to you?

It is humiliating.

Your client might never realize what just happened, and at first, you might not realize it either, but later, when you go over your notes, preparing for a witness or closing argument, it might dawn on you.

You’ve been rolled.

Right in front of the jury. A boldfaced lie. And because you weren’t prepared, you didn’t object.

Unfortunately, I see it often — so often I had to put together this class.

Important details that affect your case, from the video frame rate to the file metadata to the resolution of your images and video. From understanding how microphone placement might affect the audio recording of a voice to how the camera angle and lens type could mislead a jury in regards to suspect size, actions, and height.

Avoid the #1 mistakes made in court with video, audio, and still image evidence.

Not only avoid humiliation, but force the other side to admit their attempted deception.

How powerful it is when you stand up in court — in front of the jury — and object with, “Your honor, the prosecution has misstated the evidence.”

And then to go back in chambers with the judge while you describe how the opposing attorney is misleading, and for the judge sustain your objection in front of the jury.

Good stuff, yes?

You will hear concrete advice. We’ve saved attorneys from a lot of headaches and humiliation; we could help you too.

Why are you providing this class for free?

Why am I willing to bankroll these classes, spending our time, resources, and energy to teach classes and not charge a penny?  Because it allows potential clients to see not only our technical skill set and history of successful cases, but also to see us in action, presenting to a group, just as we do in front of a jury. If you need us to testify as an expert witness, you will know that your expert is confident, knowledgeable, and persuasive on the witness stand.

I’m tired and frustrated with attorneys making mistakes that hurt their clients! Get us involved from the beginning, when you and I have the time to watch, listen, and focus on the evidence.

This is why I put together this class.

Two MCLE classes scheduled in Southern California for the beginning of 2018 are:
Tuesday, January 9, 2018, at 1:30pm we are scheduled to teach in Glendale at a firm specializing in insurance defense, and Tuesday, February 20, 2018, at 6pm we are scheduled to teach in Culver City at a Bar Association meeting. If you plan ahead, we can get you in to one of these classes as a guest of ours. Please contact us for the details.

David Notowitz is the owner and founder of NCAVF, the National Center for Audio and Video Forensics, a full-service audio, video, and still image forensics company based in Los Angeles and providing all levels of consulting, analysis, and media preparation for evidence used in arbitration, hearings, and court — from 3D recreations of crime scenes to video production, and from forensic video and audio enhancement to testifying in court as an expert witness. Millions of dollars has been saved — and won — and many lives have been altered — due to his company’s meticulous work.
Posted in Criminal Trials Civil Trials Depositions and Hearings, Enhancement of audio and video, MCLE classes | Tagged , , , , , | Leave a comment

Police Can Not Hide Tracking of License Plate Data

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Police Can Not Hide Tracking of License Plate Data

Police Can Not Hide Tracking of License Plate Data Collected from ALPRs

The California Supreme Court ruled unanimously that police can not hide tracking of license plate data and must release to the public all the plate data they are collecting. According to the ruling, the state law does not generally exempt license plate data from public disclosure.
For many years, U.S. police departments have been using Automatic License Plate Readers (ALPR) with sophisticated surveillance cameras capable of automatically reading every visible license plate on all passing cars.

The license plate readers are important in helping locate stolen vehicles and tracking getaway cars of suspected criminals, but it can do more than that. Automatic License Plate Readers, or ALPRs, coupled with algorithms that can analyze these huge collections of data, enable police departments to hone in on hideouts of criminals by following their travel patterns and their associations with others over time.

For example, when an officer tells a computer to track a specific license plate, the computer will track OTHER license plates that pop up NEAR this main license plate number. If the nearby license plates show up more than once, the computer will alert the officer that this second license plate may be a “friend” of the main license plate.

Police Object

This powerful surveillance capability has caused concern from ordinary citizens. Police departments store this license plate and the location data for long periods. The tracking and storing of this information, without specific warrant approval from judges, could be a violation of the privacy of citizens. Organizations which requested data collected by ALPRs are the Electronic Frontier Foundation, the American Civil Liberties Union, and several news organizations.

These organizations aim to raise awareness on how much information the police have collected on innocent civilians. While some authorities cooperated and shared these records, others balked at the request, such as the Los Angeles Police Department and the LA Sheriffs Department. One of the police departments that shared their collected data was the Oakland Police Department.

The L.A. Police and Sheriff departments initially won legal challenges at state trial and the appellate courts, wherein courts found that the data was protected by exemptions for police investigations inclusive to the California Public Records Act. However, the California Supreme Court now ruled that lower courts interpreted the exemption too broadly.

California Supreme Court Overrules Lower Court’s Decision

While the state high court ruled out the exemption, it still denied — for now — that organizations can access the raw data of the license plates. According to the California Supreme Court, the license plate data can only be accessed if the organizations work out with the trial court about how they can anonymize license plate information to avoid jeopardizing the privacy of citizens.
There are surely many police departments and authorities that will not be happy with the Supreme Court’s ruling.

According to California authorities which disagree with the California Supreme Court, their decision would make the ALPRs “virtually useless.” However, refusing public disclosure would harm the public’s right to know how authorities are doing their job, and it could hurt the ability for some to defend themselves in the situation when evidence from license plate readers was used to in their prosecution.

Posted in Advice for attorneys and police on recent surveillance issues, Enhancement of audio and video, In The News - Surveillance, Trials Depositions and Hearings | Tagged , , , , , , , , , , , , | Leave a comment

Augmented Reality proof of concept allows audio recordings to visually float in 3D space

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With all the audio analysis and enhancements that we do, I am often looking at audio waveforms and spectrograms. That’s one important way we explore, measure, and judge how audio filters are impacting the original audio.

Below are examples of how a voice is seen in today’s software on a waveform (the blue signal), and a spectrogram (in orange). Both are in stereo.

analyzing audio from a voice

Waveform analysis of spoken voice

Now, a revolutionary visualization of audio signals might soon help us with our forensic audio work.

Watch this amazing new test concept using the Apple ARKit (Augmented Reality Kit). The ARKit is software included with all iPhones and iPads.

This concept test allows the user to create audio that floats in space which the user can walk through to explore the sound signal.

With the proper programming, audio filters, and acceptance in the forensics community, I can see this being the future of audio enhancement, analysis, and editing for court situations.

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Create Your Own Video Evidence and Help Solve Crimes

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Create Your Own Video Evidence and Help Solve Crimes

video evidence

Your video evidence may solve a crime.

Under normal circumstances, the police are responsible for finding video evidence, or any evidence for that matter, of a crime. The police will then process and analyze the video evidence to solve the crime and prove their case. But what if everyday citizens could have an opportunity to create video evidence that couil help solve crimes? This is more or less happening in Livermore, California.

As of 2015, the Livermore Police Department has created a database of privately owned surveillance systems so that they may determine who is in possession of potentially surveillance video systems that may have recorded useful video evidence of a crime. The police are requesting that anyone with surveillance register their system and its location with the department. If the police have reason to believe someone’s registered surveillance system may have recorded a crime, they will request temporary access to the owner’s surveillance system so that the video evidence may be extracted and analyzed by police.

Citizens On Patrol

For the police to access privately owned surveillance may increase video evidence for prosecuting criminals. However, police accessing private citizens’ surveillance may also be another step towards an invasion of privacy via 4th Amendment violations. So how is the public kept safe from police overstepping their bounds?

First, the Livermore police are not asking for permanent access or for a live stream of these private surveillance systems. Rather, the police plan to only access surveillance systems on an as-needed basis. Further, individuals who have registered their devices are under no obligation to give police access to their systems, even if police suspect a crime has been captured. Police promise to request access and only then recover pertinent video evidence.

If the Livermore Police Department’s surveillance program is successful, this may be a positive step in solving crimes faster and more efficiently. Advances in surveillance video cameras, data storage (such as cloud-based storage), and the internet have made it possible for the police to do more than what they’re attempting in Livermore, California.

Homemade Surveillance Video Evidence to Solve Crimes

Most new privately owned surveillance systems are designed to be accessed from anywhere in the world via the internet. In other words, if a user has a computer or smartphone with access to the internet, they can see a live stream from their surveillance, or they can access saved video evidence from their cameras. Advances in all this technology is such that multiple surveillance systems may be viewed from a single access point. For the police to do this would give them unprecedented access to live surveillance feeds, thus allowing them to catch crimes being committed in the act. Such efforts may be able to decrease response and investigation times, as well as help to prevent crimes from happening.

Posted in Enhancement of audio and video, In The News - Surveillance | Tagged , , , , , , , , , , , , , , , | Leave a comment

Teaching an MCLE tomorrow in Fullerton area

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We’re looking forward to teaching attorneys about the newest techniques in video, audio, and still image forensics. All examples and material taken from our actual cases.

I expect a great crowd tomorrow, so join us!
Here are the details!

Posted in Enhancement of audio and video | Leave a comment

Why Snapchats Aren’t as Snappy As They Say

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Why Snapchats Aren’t as Snappy As They Say

snapchat photo evidence

Snapchat hidden files may still be useful photo evidence

Photo evidence can often come from some very unexpected sources. Snapchat is still a highly popular app right now, especially among teens and preteens. If you are not a teen or preteen, you may need some explaining. Simply put, Snapchat is a picture-sending social media app; but what makes Snapchat different, however, is that the pictures (typically referred to as “Snapchats”) taken and sent via the Snapchat app will automatically self-destruct after a few seconds and are never seen again. Supposedly. (Unless someone screenshots them.)

What does that mean for you or a potential court case? With Snapchat’s popularity, it’s highly probable that Snapchat may become an important part of a court case. Depending on the nature of the case, the Snapchat generated photos -which have “disappeared”- may become valuable photo evidence. So then what about the photos that supposedly disappeared? Well, they don’t go away as quickly as people think.

For instance, did you know you can recover Snapchats from a phone, even after they’re deleted?

Snapchats Don’t Go Poof

snapchat photo evidenceThat’s right. Snapchats don’t completely disappear. As Richard Hickman explained to, the pictures are just given the file extension “.NOMEDIA” by the Snapchat app, which makes them invisible to most normal phone users. Now, eventually, those files will be actually wiped from the phones storage in order to make more space, but they often hang around for quite a while, and what’s more is that those “disappeared” Snapchats can be recovered from a phone.

Snapchats Are Recoverable

If you were to Google “recover snapchat photos android”(or iPhone), you’ll find many articles or downloadable programs on the topic of recovering these hidden files. Recovering the pictures properly, however, will require a forensic expert who has the right programs and knows what they’re doing. This is especially true if the pictures may be used as evidence in a case.

The Point of Snapchats Photo Evidence in Criminal Cases

snapchat photo evidenceBut why should anyone care about old Snapchat photos? Well, these Snapchats could be material evidence in a case. Cases such as a child pornography case, a family law case or child custody case, or even a civil case such as a slip and fall / personal injury case. The relevant point is that most people don’t think of Snapchats as hanging around, since the app automatically deletes the images. So someone who used Snapchat to capture evidence, but then assumed that evidence is safely deleted are probably not as likely to think they need to go back and erase that evidence. Having a forensic expert recover that hidden evidence, however, could work to your case’s advantage.

NCAVF and David Notowitz attended a photo evidence forensic symposium and heard forensic expert Joseph L. White, MS speak about a case of a man who tried to claim his Snapchats didn’t contain underage nudity. (Which can be found in the AAFS reference library.) The suspect in this case assumed he was safe as the Snapchat images had been “deleted”. A recovery of these images, however, revealed that they did in fact contain underage nudity, which was discovered through the use of forensic video analysis and software. These recovered images were then used as material evidence in the case.


When dealing with a case that involves images that may have been taken with a cell phone, it’s important to be aware that Snapchat may have been used to capture images. And even if Snapchat deleted these images, it might mean there is still hidden evidence buried on the phone’s storage. Therefore, don’t dismay if you need a Snapchat back. It is frequently possible to recover Snapchats from a phone to use in a case. All you’ll need is a little bit of digging, and a forensic video specialist, to bring them back from the grave.

Posted in Advice for attorneys and police on recent surveillance issues | Tagged , , , , , , , , , , , , , , , , , | Leave a comment

What Should Your Image and Video Forensics Expert Know?

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What Should Your Image and Video Forensics Expert Know?

Video Forensics expert

Suppose you have a case that has quite a bit of video evidence or still image evidence. You know it needs to be looked through. Or you know that an image or two will be pivotal depending on what you find out from them. The prudent thing to do would be to decide that you need a video forensics expert. But you’ve never hired one. What should an attorney be looking for in a video forensics expert?

According to the Scientific Working Group: Imaging Technology’s (SWGIT) “Best Practices for Forensic Video Analysis,” a video forensics expert should do the following:

Understand what the work entails within the forensic environment

Basically, your video forensics expert needs to know his job. He can’t just be some programmer who knows a bit about file structure. Or a video editor doing forensics on the side. He should know what needs to be done in the context of a forensic environment.

Know the subject

If you’re going to hire someone, make sure he has knowledge about your particular problem. Has he worked cases with surveillance videos before? Does he understand about violent crime? Make sure he understands the case you’re handling. Make sure your forensics expert also understands the defense or prosecution strategy you’re going to use to prove your case (or disprove the other side’s case) so that he knows the aspects of evidence to look for as he works on the video enhancement.

Know the right video and image forensic techniques

Of course, the expert may need programming, software, and video expertise as well. They shouldn’t just be a glorified private eye using internet tutorials.

Know Forensic GVideo Forensics expert best practicesuidelines (SWGDE)

There are several organizations that recommend various forensic guidelines that may be followed when evaluating or enhancing evidence. The Scientific Working Group on Digital Evidence (SWGDE) is one such group. SWGDE publishes forensic guidelines that are studied and observed by many forensic experts. SWGDE is one of many organizations that contribute to a variety of standards in acceptable forensics techniques and practices for video forensics.

Understand the “legal precedent for the use of specific image and/or video processing techniques”

Your video forensics person should know the lay of the legal land; otherwise, they might make mistakes that would keep crucial evidence out of court.

Understand and use “appropriate casework documentation”

For a similar reason, your forensics person should know how to keep correct documentation. These are just several of the guidelines given. You can find more here. Basically, you just want to make sure that the person you hire is careful, precise, and knows their stuff.

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Can You Spot All the Fakes? Images, That Is

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Can You Spot All the Fakes? Images, That Is

Video Forensics
Not sure whether a key image or video in your case is faked or original? Photoshopped images and video have become a big problem, as editing programs get more sophisticated and easier to use. Just a couple of clicks in Photoshop and you can make almost anything disappear. But what if your case has a lot of images that you can’t tell are false or real. Can you sort through lots of photos for fakes?

Right Now

Nowadays, you can get programs that will at least attempt to tell you if a picture has been altered. Some programs track compression values. Each time an image gets saved, it often gets compressed. But if part of a file is changed, that part won’t have been compressed as many times as the rest. This page explains further.

But this method of analysis might not work on a really good Photoshop job. And the process, therefore, still requires human examination.

In a case such as this, you would definitely want to hire an image and video forensics professional to use their sharp eyes.

Future Developments

Video forensics fake images

But what if you have a ton of pictures and video to go through? What then? There’s not much you can do now, except go through every picture individually, which could take forever. But people are working on a way to fix this problem.

Under a program funded by the Defense Advanced Research Projects Agency (for $4.4 million), researchers from the U.S as well as Brazil and Italy are trying to invent a machine-learning algorithm to help. This algorithm will hopefully be able to sift through loads of images and video forensic data and comb out the false from the real.

How could that help with your court cases? Well, hopefully, once this software is developed, it can be applied to all sorts of areas. It could be used to analyze all the images on someone’s computer or on a public Facebook account for evidence in a case.

Maybe someday this software will come to a video forensics specialist near you. But for now, you’ll just have to rely on their human eyes.

Referenced from: U.S. Eyes Tools to Spot Faked Images, Video

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Judge’s Shocking Ruling on Hidden Audio Surveillance

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audio surveillance

Wiretapping circa a long time ago

Judge’s Shocking Ruling on Hidden Audio Surveillance 

The NCAVF article titled “FBI Plants Audio Surveillance Outside Courthouse“ was originally posted on 05/12/2016. This is an update to that article based on current events and the judge’s ruling on evidence and the use of audio surveillance devices in the case. Please click the above link to read the original article.

US v. Joseph J. Giraudo, et al.

After hearing arguments from both sides, U.S. District Judge Charles Breyer found that federal investigators had “utterly failed to justify” their warrantless use of recording devices. In his 19 page decision, Judge Breyer wrote, “Even putting aside the sensitive nature of the location here, defendants have established that they believed their conversations were private and that they took reasonable steps to thwart eavesdroppers.”

The judge’s decision could set a significant precedent in regards to the use of hidden audio surveillance devices. According to Judge Breyer, even though a conversation is being held in public, where bystanders not party to the conversation may hear, none the less, the conversation is (at least in this case) considered private. Therefore, in order for these recordings to be used as evidence in this case, the FBI should have obtained a warrant.

At almost the same time Breyer was hearing arguments on the San Mateo case, U.S. District Chief Judge Phyllis Hamilton heard an almost identical case involving audio recordings that were also secretly recorded by the FBI, also without warrants, also right outside courthouses, and also involving real estate investors whom the FBI believed were bid rigging. This case originated just across the bay, in Alameda and Contra Costa counties, but Judge Hamilton ruled completely differently that Judge Breyer.

US v. Michael Marr, et al.

In her case, Judge Hamilton ruled that the audio evidence would be admissible. In her decision, Hamilton stated, “Having listened to the recordings at issue, the court finds that defendants did not take steps to protect the privacy of the conversations that were audibly recorded.”

Just like in Breyer’s case, attorneys for the defendants (in Hamilton’s case) argued that despite being outdoors, clients frequently have private conversations with their attorneys. Judge Hamilton, however, dismissed this argument, stating, “It has been the court’s observation that conversations near the courthouse entrance are frequently overheard by unintended and unseen listeners, even from inside the courthouse.” Hamilton, therefore ruled there was no expectation of privacy.

Have Your Cake and Hide it Too

Despite siding with the prosecution in ruling the audio recordings admissible, Judge Hamilton, none the less, also indicated, “it is at the very least unsettling that the government would plant listening devices on the courthouse steps.” hamilton’s statements are concerning. On the one hand, Hamilton says the recordings are fine, but on the other hand she admonishes the FBI agents for planting audio surveillance devices outside a courthouse.

In her decision, Judge Hamilton pointed out that part of the reason she ruled in favor of the prosecution is because the defendants , “…did not take steps to protect conversations.” Even in public, most people assume that a conversation between two people is considered private. That a nearby bystander is listening is irrelevant because that bystander is not a party to the conversation. The judge, however, seems to feel different, as her ruling reflected.

audio surveillance

The first device that was wiretapped

Same But Not Equal

There is a very stark and dramatic difference of opinion in these almost two identical cases: Judge Breyer ruled the evidence out by saying the conversations were clearly private; Judge Hamilton ruled the recordings in by saying the conversation were clearly not private. Yet in both cases, microphones were hidden in public areas just outside courthouses. This difference of opinion between two federal judges touches on an interesting idea: are wiretapping laws outdated? A wiretap may be defined as, “ the monitoring of telephone and Internet conversations by a third party, often by covert means.” This would include setting up a hidden audio surveillance device such as a microphone outside a courthouse. The word “wiretap” comes from the 1890’s when the actual phone’s wire was “tapped” by plugging into it so it could be listed to or recorded by the third party. This language shows just how outdated these laws may be since so much of today’s “wiretapping” is done wirelessly.

Need for New Laws Regarding Audio Surveillance

Both of these cases, however, seem to address a subject that affects everyone (not just these defendants). Recently, the government has been placing microphones and recording conversations on city buses, trains, and other locations, seemingly without the consent of riders. Activities like this would appear to be a clear violation of our 4th Amendment rights. So what may be the future of wiretapping laws? When the authors of these wiretapping laws first created them, they did not foresee today’s smartphones, button cameras, and microscopic digital recorders. Is it time to reconsider what constitutes wiretapping in the 21st century?

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Can You Use a Selfie to Find Out a Kid’s Age?

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Can You Use a Selfie to Find Out a Kid’s Age?

Forensic Image Analysis

Selfies can be used to identify age of adolescents

Did you know you can accurately guess the age of a child from the diameter of their pupils? Pupil diameter seems to increase pretty predictably as a child grows, unlike other features of the face, according to Neeka Parker’s assessment of pertinent studies in her paper “Age Estimation of Adolescents Using Eye Measurements from Various Angles in Videos.”

Did you also know that kid’s love selfies? I probably don’t have to tell you that a selfie is a picture a person takes of him or herself. Because of this, the selfie is often at a unique angle from other pictures. Selfies, though, are almost epidemic, especially among younger people and millennials. (Over 55% of millennials say they’ve taken a selfie.) Forensic analysis of selfies as regards to a young person’s age could be an important part of a legal case.

But can you figure out a child’s age from their pupils in a selfie? In her study, Neeka Parker wanted to find out what selfie angles and cellphone pictures did to the angle of an adolescent face and to how well you could see their pupils.


With permission from their parents, Parker gathered twenty-one children from ages eleven to nineteen, twelve girls and nine boys, some African-American and some Caucasian, with one Mayan. Most of these children had brown eyes, which will be important later.


With these participants gathered, Parker had to deal with some variables in the way eyes change. Pupils can be affected by lighting, medication, or even just a person’s mood. Parker asked her participants questions about their mood and medication so she could account for those variables. And, of course, she made sure the lighting was controlled.


Parker took pictures with an iPad and a Nikon D3100 camera and video with the Nikon. She took reference pictures and then had the participants take selfies, which were analyzed in Photoshop.


Selfie Forensics
In the end, Parker found that since most of her participants had brown eyes, generally she could only distinguish the pupil on the Nikon images but not the iPad images or the Nikon video stills. This made further analysis and measurements difficult. Note that the pupil diameter is the most important part of judging a child’s age by their face and that brown is the most common eye color.


Although Parker did compare her device, the iPad, to other smartphones and concluded that camera hasn’t improved, at least in the iPhone, it would have been useful if Parker had included more imaging devices, including actual cellphones in her study. In my experience, a teenager would rather be caught dead than using something clunky like a tablet or iPad to take pictures. Selfies are the domain of the smartphone, which is light and convenient to use when taking pictures with your arm stretched awkwardly.

What does this mean for determining children’s age in the forensic image analysis of selfies? Parker says more research needs to be done. But right now it looks like whether your selfie is useful depends on what device it was taken with. She also pointed out it’s possible other ways besides pupil diameter may be needed to judge age in a selfie. But as phone cameras get better and better, it’ll get easier to figure out a child’s age and tons of other useful information, from the humble selfie.

Want to know more about forensic image analysis of selfies? You can read Parker’s research paper here.

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