poison/razor blades in halloween candy/treats?

Halloween, when i was a kid was fun, we would be out late, with out parental supervision, and mom only wanted to "check " our candy when we got home so she could snag what she liked first! i remember the talk of tainted treats, poison and razor blades etc… my question is has there ever been any documented cases of someone getting or being a victim of malicious Halloween candy tampering? or is it a silly urban (suburban) legend? i was told or heard a report once that stated the only 2 documented incidents involved a child who was left a large inheritance, and members of his own family who on two consecutive Halloweens tried to kill the child by poisoning and putting razors in his Halloween candy. is any of that true or…?

Some good info on poisoned Halloween candy from Snopes.

What you’ve heard is basically what’s known to be true - there have been rare cases of it happening, but in all cases it was found to be a family member who did it, not a neighbor giving away candy.