Police say the most recent attack happened just two days ago. All have happened at the Mills Apartments off Bissonnet and the West Sam Houston Tollway.
Investigators are asking for help in identifying the two men. They say one is a lookout and the other is an armed robber and rapist. The victims appear to be chosen at random.
"They're usually approached either coming from the car, or right before they get to their apartment," said investigator Ron Churchill with the Houston Police Department Special Crimes Unit. "They're alone and a gun is pulled on them and they are taken to another location where the act occurs."
Both suspects are described as black males. One is 17 to 21 years of age, about 5-foot-5, with a small, but slightly muscular build. He was believed to be armed with a revolver. The other suspect is in his 20s, about 6 feet tall, with a medium to thick build.
In all three incidents, the armed suspect forced his victims at gunpoint into a vacant apartment where he sexually assaulted them. In at least one of the incidents, the suspect fired a weapon into the air. The second suspect was present in at least two of the incidents but did not participate in the assaults.
Residents are terrified, and many say they are taking extra precautions.
Anyone with information in these cases or on the identity of the suspects in the composite sketches is urged to contact the HPD Special Crimes Division at 713-308-1100 or Crime Stoppers at 713-222-TIPS.