ROCHESTER HILLS, Mich. -

Christine Shell is on edge after finding out one of her neighbors at Woodside Apartments in Rochester Hills was sexually assaulted.

Police say about 1 a.m. Thursday morning the woman was asleep on her sofa when she woke to a man standing over her. The man forced the woman to perform a sex act. Before leaving, he told the woman, "Please do not call the police."

Well, she did. Investigators brought out a K-9 unit and tracked the man for about 100 yards before losing the scent.

"The police have been coming in and out quite a bit," said Shell.

Police say the man made his way into the woman's home through an unlocked sliding glass door.

"My doors and windows sometimes are open," said Shell. "They need to be locked now, even more."

Apartment managers are reminding tenants to do just that. A detective on the case says there is a witness who police hope to get a better description of the suspect from.

Police released the below sketch of a suspect on Friday.