The Austin Texas Yogurt Shop Murders:

"The Yogurt Shop Murders was a case involving the murder of four teenage girls in a local yogurt shop in Austin, Texas. The murders occurred on December 6, 1991 where the shop was then set aflame. The bodies of Amy Ayres (13), Jennifer Harbison (17), Sarah Harbison (15) and Eliza Thomas (17) were subsequently discovered that night."
Sheldon:
For awhile after this happened, the police did a round up of "PIB's" (People in Black), looking for anyone that might have been involved, thinking it had something to do with the occult. I knew Goth kids that bragged about getting picked up by the police during this time.
Just for the record, I was living in Houston when this happened, but since moving to Austin, I have worked with a woman who was friends with one of the Mothers of one of the murdered girls, a suspect that worked next door to the shop, the mother of a man that was on the jury of one of the trials, and I used to work at a costume shop very close to the shopping center.

They have still not solved these murders. The guys they found guilty keep turning out not to be the right guys... I hope they do catch the right guys though.
(click the pic to read all about it!)