Howell was last seen playing with his sister, outside of their family's home on West 13th Street in Sterling, Illinois on May 28, 1969. They were going to build a cage for Howell's birds, and his sister went inside for tools. When she returned, the boards Howell was going to use to make the birdcage were scattered along the street and Howell had vanished. A neighbor reported his disappearance to police at approximately 10:35 p.m. that same day, after his parents spent the whole day searching for him.

Howell had a somewhat chaotic childhood. He has two brothers and one sister. He and his siblings were sent to an orphanage after their parents divorced in the early 1960s. Two of the Howell children were later sent to live with an aunt, and Howell and one of his brothers went to a foster home. All the children had gone to live with their mother and stepfather by 1968. Howell's mother stated her son was afraid of the dark in 1969 and she did not believe he would have run away from home.

There were several reported sightings of Howell after his disappearance, but he was never found. Searchers looked in gravel pits and water areas, particularly Elkhorn Creek and Rock River. His family members all took polygraph exams and were cleared of suspicion in his disappearance in 1998. Howell's case remains unsolved; the circumstances surrounding his disappearance are unclear.