TRACY (CBS13) – Police in Tracy have arrested a woman in connection with a homicide that happened in September.

On the morning of November 5, police arrested Nicole Diaz, 28, of Tracy, for her suspected involvement in the homicide of Nikolis Martinez on September 21 in the 200 block of W. Carlton Way. She was booked into the San Joaquin County Jail, according to a Tracy Police Department statement.

Enrique Guillen-Valles and Nicole Diaz (credit: Tracy Police Department)

Enrique Guillen-Valles, 21, of Tracy,  has been identified as a second suspect in the homicide. He is believed to be armed and dangerous.

Police have the vehicle allegedly used in the homicide, a grey Chrysler 300.

Police do not believe this was a random act of violence, and that the suspects and the victims knew each other. The case remains under investigation.

Anyone with information about the shooting is asked to contact Detective Jesser at (209) 831-6640. You can also contact Tracy Police general line at (209) 831-6550 or Tracy Crime Stoppers (209) 831-4847 / 24 Hours a Day – 7 Days a Week, TEXT: Text “TIPTPD plus your message” to 274637 (CRIMES).