(Umatilla, OR) -- The FBI believes there may be more victims of a child sexual abuse suspect on the Confederated Tribes of the Umatilla Indian Reservation. 41-year-old Aaron William Pizer recently pleaded guilty to two counts of sexual abuse of a minor and one count of abusive sexual contact. He was arrested in 2024 in connection with the abuse of two children on the reservation over the past nine years. Investigators are asking anyone with information is asked to contact the FBI.