I saw this thread when scanning the forums this morning, and want to chip in with another unsolved urban murder case.
When growing up in Philly back in the 1960's, one of my best friend's kid sister was murdered, and it has never been solved.
Her name was Dolores Della Penna, and she was murdered in Philly in 1972. She was only 17 years old, and her body was completely dismembered.
Horrible crime, and never solved by the Philadelphia police.
Dolores Della Penna