(CNN) -- After authorities used thermal-imaging equipment and ground-penetrating radar to search outside murder suspect Anthony Sowell's home and a property next door in Cleveland, Ohio, FBI agents marked areas outside the home with spray paint, CNN has learned.
The high-tech search could mean police plan to dig for more possible victims this week, but police will not reveal their plans. The remains of 11 women have been found inside and outside Sowell's home.
The registered sex offender, who served 15 years in prison after pleading guilty to attempted rape, now faces five counts of aggravated murder, rape, felonious assault and kidnapping in the deaths.
Asked Sunday whether any evidence was found in the search Friday night and Saturday, Cleveland Police Lt. Thomas Stacho told CNN, "We will evaluate yesterday's examination and determine how to proceed in the coming days."
He added, "No evidence was taken from either Sowell's home or the home next door."
"We're finished using the high-tech equipment, and the results of those searches have been provided to the Cleveland police department for review," said FBI Spokesman Scott Wilson.
On Friday night and Saturday, FBI agents used sophisticated thermal-imaging equipment and ground-penetrating radar to search both properties at the request of Cleveland police. Wilson told CNN the radar "can determine whether there are certain structures under the soil."
Areas singled out with paint outside Sowell's home appear to indicate police found something worth pursuing.
Further investigation could require additional search warrants and help from the Cleveland coroner's office. Both were used to find the previous remains, which included a skull hidden inside Sowell's home.