Tammy Erwin was an 18-year-old woman from Riverside, California, who was murdered on April 16, 1989. Cartridge cases found near her body linked this killing to other murders in the region and helped investigators realize they were dealing with a serial offender.

Erwin’s murder became part of a broader investigation into a string of homicides across Riverside, Orange, and San Diego counties from 1988 to 1995. The suspect named in these cases, Andrew Urdiales, was later apprehended in 1997 in Chicago and was connected through further investigation and forensic work to killings in California, including Erwin’s. If anyone knew Tammy, saw her on April 16, 1989, or has information about that area near Palm Springs, please come forward.