Unless one has been ordered to preserve evidence already for a pending court case... proving that someone knew said information was valuable as evidence, and willfully destroyed it knowing so, might be extremely difficult.
There are very specific rules for proving destruction of evidence. For a criminal case the burden proof in the US at least is "beyond a reasonable doubt", so someone would likely have to prove that you knowingly destroyed valuable evidence before you'd get in big trouble. And if you haven't already been served with something saying you need to preserve evidence, they might not have any claim to information they had no idea existed beforehand, especially if you don't talk.
Believe this is bad legal advice. They would only need to prove you destroyed information with intent to impede an investigation/case. They would not need to prove something convicting or weighing was destroyed.
> They would only need to prove you destroyed information with intent to impede an investigation/case
Which requires them to prove they know that device likely contains relevant information. Just being party to a court case doesn't mean you're forbidden from deleting anything ever again... like I said there are very specific rules for evidence, and one cannot begin to claim something relevant is destroyed if you can't even show that you had any idea what might have been destroyed in the first place.
It mostly hinges on your intent, i.e. what they can argue is your understanding of the information you destroyed, not theirs. It unfortunately can be far-reaching, including into the past.
You're right that in normal circumstances you can routinely delete records for data hygiene, to save money, as part of a phone repair, and so on, unless you've been court ordered otherwise.
You're also assuming they even think something may have been destroyed in the first place. A wiped/clean device is not necessarily indicative of anything. For a criminal case they still have to prove beyond a reasonable doubt that they believed the device had something they wanted on it (and now it doesn't), with evidence to back that up... not just "well it COULD have had something". That might fly a bit farther in civil cases but not criminal.
And remember that without a court case alleging something in the first place, they wouldn't even have access to the device to know 1. it existed and 2. it might have had something useful on it. If I had two devices in my house and they're both clean, you can't just say "oh we think one of them had some evidence that was destroyed"... you need some kind of proof that it at least likely contained something relevant in the past before you can even begin to presume it might have been destroyed.
Nope--they don't need to prove they believed the device had something they wanted. That's just the motivation for them to go after you for inconveniencing them.
Same for your second paragraph: "oh we think one of them had some evidence..." - that's not how it works! It's your intent to destroy evidence that is the crime, not whether you destroyed evidence. They do not need to prove you destroyed evidence or even likely storage of evidence to get you convicted.
This is the main thing you're saying that is bad legal advice.
For your other point, yes, if they can't tell anything happened, or it seems like an accident, then you're probably going to get away with it. This happens a lot. I think that's a different topic. Original topic was: if you wink at your phone or use a weird finger (or some other visible gesture) and now your phone's wiped, could you get in legal trouble for that sequence of events.
> It's your intent to destroy evidence that is the crime, not whether you destroyed evidence.
Accidentally destroying evidence can still carry a serious penalty, but yes the intent is generally the most important. But absent intent, it can still help the prosecution to know the device had something useful to them on it.
What you seem to be referring to would be obstruction, whereas the entire parent thread was specifically discussing destruction of evidence. Fair to point out that there are other offenses that could be charged, but misleading to imply it’s the same thing.
