Police charged a 38-year-old man with aggravated assault Friday for attacking a part-time professor near Dupont Circle last weekend, which has left the victim in a coma.

James Brown of Southeast D.C. was arrested for attacking Jason Chambers, a fencing instructor in the department of exercise science, on S Street near Connecticut Avenue, according to a Metropolitan Police Department release.

Chambers was taken to GW Hospital, where he remains on life support, WJLA reported. He was wearing a silver Halloween costume Sunday at the time of the attack.

Officers found the 39-year-old “almost motionless” on the sidewalk at about 4:20 a.m. after the suspect had fled the scene. Chambers was “unable to communicate and provide details of the assault,” according to a police report.

MPD assigned homicide detectives to the case because of the seriousness of Chambers’ injuries.