Alrighty, that sounded bad… Deleting a file probably won’t land you in jail unless you are doing something illegal in the first place.
The idiot who attempted to extort money with a “collar bomb” was most likely caught due to leaving a message on a USB flash drive that he had deleted files from.
The ONLY safe way to remove data from a hard drive, flash drive, tape drive or other types of media is to physically destroy it. Our friend Brent over at ShredDisk can help you with that. Don’t make the mistake of deleting files only to find they are recoverable.
Here’s a link to the original article which mentions additional clues that were used to find the “collar bomber”, such as meta data in a recovered Microsoft Office Word document.