The Los Angeles City Council on Wednesday offered a 500,000-dollar reward for information leading to the arrest and conviction of a serial killer believed to be responsible for at least 11 murders.

Dubbed the "Grim Sleeper", the suspect has killed 11 people in Los Angeles between 1985 and 2007, according to the Los Angeles Police Department (LAPD).

The LAPD established a cold case unit in 2001 to investigate unsolved homicides. It was not until 2006 that detectives discovered the 11 murders were connected through DNA and ballistics evidence.

Fifteen suspects have been eliminated as the serial killer, said LAPD Capt. Denis Cremins.

"This individual committed several homicides from 1985 through 1988, and then there was a 13-year hiatus. What accounted for that gap we still don't know," Cremins said.

Ten of the victims were young, black women. Their bodies were left in a corridor along Western Avenue in South Los Angeles. Authorities believe most were working as prostitutes, and some of the victims had been sexually assaulted, the Los Angeles Weekly reported.

One woman -- identified as Victim No. 9 -- survived an attack by the Grim Sleeper. The woman was shot in the chest and raped. The bullets removed from her chest matched the gun used on the first eight victims.

Victim No. 9 described the killer as a 30-ish black man with short hair, driving a rust, red or orange Ford Pinto, according to the weekly.

(Xinhua News Agency September 4, 2008)