By: Scott McCabe
Examiner Staff Writer
06/07/09 7:13 PM EDT A federal judge sentenced an MS-13 gang member to life in prison for gunning down a rival gang member on the streets of Springfield.

Federal prosecutors said Sergio Amador, 29, was a member of a New York clique of MS-13 known as Surenos Locos Salvatrucha, an offshoot of the gang Mara Salvatrucha, or MS-13. Two years ago, Amador was sent to Northern Virginia to help a local MS-13 clique fight the 18th Street gang. With roots in Los Angeles, Central America and Mexico, the Hispanic gangs are considered rivals.

Amador joined Oscar Omar Lobo-Lopez, the leader of the Hollywood Locos Salvatrucha clique, in the hunt for Melvin Reyes, a man who they believed belonged to the 18th Street gang. Prosecutors said the rules of MS-13 required members to attack their rivals whenever they see them.

MS-13 members were angry because Reyes had visible tattoos that showed his allegiance to 18th Street. The gang patrolled the Hispanic section of Springfield warning people that they should contact Lobo-Lopez if they ever saw Reyes.

On May 5, 2007, members of the Hollywood Locos Salvatrucha spotted Reyes in the Springfield Garden apartments on the 7200 block of Commerce Street, near Old Keene Mill Road. Amador and Lobo-Lopez, armed with handguns, chased after Reyes and shot him. Reyes fell to the parking lot ground.

As Reyes lay wounded, prosecutors said, both men stood over him. Lobo-Lopez ordered Amador to “finish him,â€