Both sex assaults occurred at East Park Apartment Complex, located near Algonquin Road and Algonquin Parkway, in Rolling Meadows. In both incidents, the man knocked on the victim's door, forced himself inside and assaulted them.
The most recent incident occurred in the early morning on June 30. The man had a knife and ran from the area after the incident.
The second sexual assault occurred Jan. 14.
Police suspect the man is also involved with two break-ins in February and December.
The suspect is described as a Hispanic man, between 5-feet and 5-feet-3-inches tall, weighing about 160 pounds.
Anyone with information is asked to call the tip line at 847-506-6024 or the Crime Stoppers Hotline at 847-590-7867. Crimestoppers offers anonymity and up to a $1,000 reward for information leading to an arrest.