Fairfax County police have released a sketch of a teen they said robbed and sexually assaulted a woman in her Chantilly area home around 9:30 a.m. Monday.

Police released this sketch in the assault and robbery of a Chantilly woman. (Courtesy Fairfax County Police Department)

The suspect, who was wielding a knife, attacked the suspect and then fled after she screamed, police said.

It does appear the victim knew her assailant, police said. Authorities said women should be on guard in the area.

The suspect is described as a black male, 15 or 16-years-old, and about 5’7” tall. He is thin and was wearing a shirt and blue jeans at the time of the incident, police said.

Anyone with information is asked to call Fairfax County police at (703) 691-2131.