Now detectives are looking for 35-year-old Jesse Bernal Gutierrez. Police said Gutierrez and Duran were seen arguing near Duran's job.
Witnesses said the suspect had accused the victim of having an affair with his girlfriend.
Officers said Duran was shot several times and left in an alley.
Anyone with information on the crime is asked to the Los Angeles Police Department at (818) 832-0554.