Thanks for the presumption of innocent until proven guilty!
Firstly i do regard myself as having done no wrong
secondly, what are u guys jumping up and down for i'm asking a legitimate question:
How can i prove what they have read.
i think i have the answer but a technical walkthrough was what i was searching for
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it would be nice if i could prove they had done wrong!
i was just curious if it was an easy process to see what had happened to a computer
Your questions were answered. I'll run it down again.
When a forensic lab gets a hold of your computer they will image the drive without even turning on the computer. The reason for this is to preserve all logs and ensure that turning it on doesn't do anything to the drive. The chain of custody and evidence MUST be preserved. They likely took your Mac, walked it into the office, sat it down, opened it up, grabbed the drive or left it in place if possible, and began the imaging process.
Your computer then sat there, likely off and never even turned on for many months until they felt they were done with it and had everything they wanted. If they turned it on, it could be in the OS X log files. You can prove it was turned on but that does not prove anything was copied. You will never prove that until they present evidence that you know was on your computer to you in court.
There is no smoking gun. There is no reason for you or anyone else to believe the police did anything wrong. They had a warrant, they seized your property, they did whatever they were going to do and they returned it. As far as anyone can tell thus far, they did everything by the book. If it is decided that they did wrong, they did not have justifiable cause for a warrant, and your copied files should not have been copied then you MAY get an apology, the "evidence" will not be allowed in court (I believe this to be true for the UK), and you will go on your way.
Guilty? You think we're saying you're guilty? **** no. I'm saying, personally, that I would shut my damn mouth if I were you. Guilty or not, the police had some sort of reason to obtain a warrant, the warrant was given, the warrant was issued, and they did what they did. I'm only saying I'd keep my mouth shut because even if I knew what they were looking for, I don't want to screw myself if they're building a case against me. Trust me, they didn't just get a warrant because they thought it would be fun to see what's on your computer.
You cannot prove what they read, what they saw, or what they listened to. Whatever they present as evidence is likely less than what they read and saw. What is presented is what they wanted not junk they don't care about.
Call your lawyer. I bet he or she will tell you there is no way to find out what they read/saw/listened to when they had your computer.
If you want straight up technical walkthrough on how they accessed your drive without even turning the computer on then I think there is some googling in your future. There are systems/software that will do this and I think one was noted above.