Zach Warren

Zach Warren is a friend of Sam's from Stanford, and is the brother of Rebecca (Becky) Warren.

In 1.06 Skin Zach is arrested for the murder of his girlfriend, Emily. While Zach is detained, his sister seeks the help of Sam and Dean in order to prove his innocence. Zach is later released by the police when a new suspect, Dean Winchester, turns up.

A shapeshifter wearing the physical appearance of Dean was caught attacking Becky and was later found dead at her house.