1.70. A man driving his car turns on the radio. He
then pulls over to the side of the road and shoots himself. (This is
different from #1.71.)

1.70 answer: He worked as a DJ at a radio station. He decided to kill
his wife, and so he put on a long record and quickly drove home and killed
her, figuring he had a perfect alibi: he’d been at work. On the way back he
turns on his show, only to discover that the record is skipping.

1.70a. Variant: The music stops and the man dies.

1.70a answer: The same, except it’s a tape breaking instead of a record
skipping. (from Michael Killianey) (See also #1.31a, #1.59, and