One thing this guy has going for him is that he did return the laptop to you. I think he deserves a little credit for that.
Although if you did give them that information and they still couldn't pursue it, there's not much else you can do (except, of course, bang your head against the wall in frustration).
The officer said, "If we followed every one of these calls, we'd never get any actual work done."
If it turns out he bought it legitimately without knowledge of it being stolen that's fine, but he still should have been turned on to the fact it's filled with someone else's crap and the username is not his. Ignorance is no excuse, even though it may be commonplace.
Personally I just don't sell hard drives. They get destroyed. I don't have anything illegal or immoral on there, I just figure, I've had financial info on there, pictures, etc, and who knows what somebody else might do with that.
Possible? Yes.
Likely? No.
This whole story screams promotion for Backblaze, it is also the first tag of the article.
That's still theft, unless he turned into the police. Since the owner filed a police report that scenario is unlikely.
Its not like Mark is a hard guy to Google for or unknown in Boston.
This is like people who, when told I'm from Russia, ask me if I know Dmitriy. Why, yes, I know several dozen.