@Jezibaba This sounds like a defense attorney trying to justify not finding what he wants to find.
I haven't been following the details of this development, so forgive me if I misstate something, but I've been a part of a fair number of forensic investigations like this.
Defense would have been given an exact copy of the drive, which would include any "free space". The vast majority of those 4TB is probably either "empty" or entirely irrelevant.
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@Jezibaba
Out of those 4TB, I would be absolutely shocked if they manually review even 100mb worth of actual documents/emails. They may review up to a TB of photos/videos depending on the nature of what they are looking for, but that's really not a lot when most phones are recording in 1080p/4k, and photos are like 10-20MP.
Long story short, if they are complaining about a single 4TB drive they've either never done this before, or they are trying to make a mountain out of a mole hill.
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@Jezibaba
They will have a forensic expert, or a team of them, using specialized software to comb through the drive and divvy up the entirety of its contents into easily classifiable chunks.
Documents go to one place, emails to another, images, video, deleted files, browser history, system files, etc., will all be separated for easy review. Then they will run various keyword searches and filters on the files to further narrow it down.
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