A woman who was jogging Wednesday night along the Capitol Crescent Trail was sexually assaulted by a man who attacked her from behind and rendered her unconscious with a choke hold, according to the U.S. Park Police.

Police said in a statement that the assault occurred about 9:15 p.m. along the trail north of Three Sisters Islands near Fletcher’s Boat House. Police said the woman, described only as an adult, awoke as the man was sexually assaulting her.

The victim screamed, police said, and the attacker ran toward the boat house.

He is described as a black male with a medium complexion, standing 5 feet 8 inches to 5 feet 11 inches tall and weighing between 180 and 200 pounds. He has a muscular to fit build, dreadlocks three to four inches long and a light scruffy beard.

The victim said he was wearing a white shirt, possibly a tank-top with the sleeves cut off and long black shorts. Police said he did not show a weapon.

Anyone with information about the attack is urged to call Det. Glenn Luppino at 202-610-8750. The U.S. Park Police tip line is 202-610-8737.