HOUSTON -

Police have released a sketch of a man wanted for sexually assaulting an elderly woman in west Houston.

Houston police said the attack happened on May 14 in the 2700 block of Wallingford.

Officials said the suspect knocked on a 67-year-old woman’s door. When she answered, he forced his way in, hit her with his hand and raped her. The grandmother was left bruised and battered, and police need help finding the person responsible for the attack.

Investigators describe him as a black man in his 30s, about 5 feet 10 inches tall, with a slim build and muscular shoulders. He had a thin mustache and goatee.

“One of the most distinctive things is that he had a green backpack, and for a guy in his 30s, that's a little bit strange,” said Darcus Shorten with the Houston Police Department. “We're hoping and pleading with the public that we can try to find this guy.”

Investigators believe the man may live in the same apartment complex as the woman or in the apartments next door.

Anyone with information about the suspect's identity is urged to contact the HPD Special Crimes Division at 713-308-1180 or Crime Stoppers at 713-222-TIPS.