On Sunday, volunteers scoured 40 of those homes, looking for any additional victims of Michael Madison, the man charged in the latest slayings.
A foul odor reported by a neighbor led to the discovery of the bodies and the arrest of Madison, 35, who served four years in prison for attempted rape and a drug offense.
At a court hearing Monday, Madison was ordered held on $6 million bail. He did not enter a plea.
The medical examiner has yet to establish the victims' cause of death; two were too badly decomposed to identify.
Authorities over the weekend said the victims were killed six to 10 days earlier. But the charges read in court specified a wider time frame for the alleged crimes — days or months before the bodies were found.
In May, Cleveland was electrified by the discovery of three women who authorities say had been held captive for a decade in a house in a rough neighborhood dotted with boarded-up homes on Cleveland's west side.
Ariel Castro, a former school bus driver, has been charged with nearly 1,000 counts of kidnapping, rape and other crimes and has pleaded not guilty. Many questioned how he could have held the women for so long without someone noticing something wrong.
Four years ago, Cleveland was shocked by the arrest of Anthony Sowell, who stalked and killed 11 women on Cleveland's east side and hid the bodies around his house and yard. He was found guilty in 2011 and sentenced to death.
Many of Sowell's victims were drug addicts who were never reported missing. Law enforcement authorities were accused of fostering an environment that made residents, many of them black, reluctant to call police.
That mistrust led to the creation of insular islands in poor neighborhoods that make it easy for predators like Sowell to operate, said James Renner, a Cleveland investigative reporter, film producer and author of "The Serial Killer's Apprentice," about 13 unsolved crimes in Cleveland.