Aug. 7 (UPI) — A 15-year-old boy has been charged with randomly stabbing a man to death at a southern Illinois bus stop while wearing a clown costume, authorities say.

Illinois State Police said the juvenile was formally charged with first-degree murder on Thursday in connection with the slaying of 78-year-old John W. Allen of Jennings, Mo., while Allen was waiting for a bus Monday night in East St. Louis, Ill.

East St. Louis Police Department responded to a report of a body lying in the street and discovered Allen, whom they determined was attacked by someone wearing “a clown outfit.”

Special investigators with the Illinois State Police quickly tracked down the 15-year-old at a residence and took him into custody, they said in a statement.

Allen’s family said he probably was killed while he was making one of his regular unannounced visits to his older sister in East St. Louis.

“We were always concerned about him coming over without calling, but he just enjoyed being with his sister,” Allen’s niece, Tania Stanford, told NBC News.

East St. Louis neighbors told KSDK-TV they spotted the teenager going door to door in the area, peering into windows and twirling a knife.

One neighbor provided the station with doorbell camera of the suspect looking into the lens and saying, “I have a gift for you.”