Franklin, 57, is accused of killing 10 women between the years 1985 and 2007. The 14-year pause led to the killer's nickname of "Grim Sleeper." Police are looking at more than 30 other cold case files to see if they can tie him to other unsolved slayings.
He was captured July 7 after police linked his DNA to evidence left at the scenes of the slain women, all of whom were murdered within a few miles of Franklin's South Los Angeles home.
Franklin was originally set to be arraigned July 27, but that was postponed due to an undisclosed conflict of interest for his then public defender.
In the past two weeks, he has been assigned a new private attorney. Louisa Pensanti is working the case pro bono.
"This is a very complex case," Pensanti said Monday. "It involves 10 homicides and one attempted homicide. All of the evidence must be reviewed and investigated."
Franklin will be back in court on September 14 when a pre-trial date will be set.
The judge in the case said the trial process could last three years.
The Associated Press contributed to this report.