HOUSTON -- Houston police and Crime Stoppers hope a reward and a composite sketch will stop a sexual predator who has exposed himself to students at three area schools, KPRC Local 2 reported Saturday.

Officials said that on April 23, shortly after 3 p.m., a man called an 18-year-old Stratford High School female student to his red Jeep Cherokee pretending to want directions. When the girl approached, the man exposed himself and asked her for a sexual favor, police said. The girl walked back toward the school.

Police said the man then drove to Memorial High School, where he walked onto the campus and exposed himself to a 15-year-old girl sitting by herself waiting for a ride. He asked her several times for a sexual favor, and the girl walked inside the nearest school door, according to officials.

Minutes later, the man exposed himself to a 13-year-old girl waiting for a ride at nearby Spring Branch Middle School. She walked immediately into the school.

Surveillance cameras at the schools revealed photos of the man on foot at the high school and of a red SUV.

A witness described the vehicle as a red 2002-2004 Jeep Cherokee sport utility vehicle.

The suspect is described as a black man in his early 20s, between 5 feet 9 inches and 6 feet tall, with a lean, muscular build. He wore a white ball cap, white shirt with blue stripes, blue or black mesh athletic shorts and white athletic shoes.

Crime Stoppers will pay up to $5,000 for information called in to the 713-222-8477 tips hot line that leads to the identification, arrest and charging of any suspect in this case.

All callers remain anonymous.