Police said a woman went to a concert Friday in the area of ​​Lake Shore Boulevard East and Coxwell Avenue, where she encountered a man.
He befriended the woman, police said, and drove her to a nearby park, where he allegedly sexually assaulted her.
On Saturday, police identified the suspect as 29-year-old Tyler Butler.  He is wanted on two counts of sexual harassment, forcible restraint and overcoming resistance by choking.
Police are asking anyone with information to contact them at 416-808-7474 or Crime Stoppers anonymously at 416-222-TIPS (8477).