Los Angeles (CNN) -- Los Angeles detectives have vastly expanded their investigation into the "Grim Sleeper" serial killer case and are now looking at whether any of 230 murders are connected to the alleged slayer, police said Wednesday.
In April, police were investigating the Grim Sleeper's connection to 55 unidentified women -- a quarter of what they're now probing -- whose photographs were found among 180 videos and photos taken from the Los Angeles home of Lonnie David Franklin Jr.
Now, authorities have widened their inquiry to include all homicides that occurred in a general area of south Los Angeles where Franklin lived from the 1970s, when he got out of the military, through the 1980s, police spokeswoman Karen Rayner said Wednesday.
That amounts to about 230 murders, and even though some had been believed to have been solved, police "are taking a second look at all of them," Rayner said.
Franklin, 58, is charged with the murders of 10 women as well as one attempted murder. He has pleaded not guilty to all the charges.
He is accused of killing females ranging from ages 14 to 36 between August 1985 and January 2007. Many of the victims were prostitutes, authorities said. Most of the victims were discovered dumped in south Los Angeles alleys and covered with debris, authorities said. All victims were shot; some were strangled too, an indictment alleges.
Prosecutors said they will seek the death penalty against Franklin.
Prior to his arrest in July 2010, Franklin had worked for a time as a garage attendant at a Los Angeles police station, authorities said.
A pretrial hearing for Franklin is scheduled for November 7, according to the prosecutor's office.