The local police department's social-media person is fond of posting historic photos and asking if people can identify where they were taken. This morning they posted a 1960s photo of an accident involving a car and a telephone pole that I concluded was only a few blocks from me, and said, "tell us as much as you can about this photograph."
So I biked over and found the date nail recording the year the telephone pole was put up, and replied with a photo of it:
I'm not sure this exactly qualifies as being an armchair detective any more, though.
Crossposted from Dreamwidth (original here), with comments. Comment here or there; comments here will eventually be duplicated to there.