Warrenville police are seeking information about a July 30 home invasion and sexual assault.
Authorities said an offender entered a home on the 500 block of Country Ridge Drive through an unlocked patio door about 3 a.m. and assaulted an adult woman as she slept.
The victim was the lone occupant of the house at the time. She was taken to a hospital for treatment of injuries related to the sexual assault, authorities said.
Deputy Chief David Schar said he could not reveal many details of the investigation but police were working to develop a description of the attacker.
"We're hoping to develop some leads by reaching out to the community," he said.
Schar reminded residents to be "diligent in securing their homes and vehicles" and "watchful of their surroundings."
Anyone with information on the case is asked to call police at (630) 393-2131. Other suspicious activity should be reported by calling 911, police said.