DeAngelo was last seen at his family's residence in Houston, Texas on April 17, 1997. He has never been heard from again.

DeAngelo was taken into state custody at age seven months, when his mother, Patricia McNeil, was convicted of theft and sent to prison. After her release she got permission to visit DeAngelo and his brother. In December 1996, the boys were permitted to live with her, though they remained officially wards of the court.

In March 1997, child welfare workers noticed a bruise on DeAngelo's face. Patricia told them he had accidentally fallen, but they suspected abuse and called DeAngelo's day care center for information. In mid-April 1997, Patricia removed DeAngelo from the day care center. He has not been seen or heard from since. When asked about his whereabouts, she claimed he was with Manuel Ferreira, whom she said was his father.

Ferreira is a native of the Dominican Republic and resided in the Memorial area of Houston in 1997. Patricia said she did not have his address or telephone number. She gave police a pager number, which turned out to belong to someone unconnected to DeAngelo's case. Investigators eventually located Ferreira in the Dominican Republic; he had fled to there after jumping bond on a cocaine charge. He denied being DeAngelo's father, did not have the child with him and did not know where he was. That and information gleaned in interviews with relatives, friends and acquaintances of Patricia and Ferreira lead police to believe Patricia's story was false.

DeAngelo's brother told investigators that he had seen his mother beat DeAngelo with a belt. Patricia was later sentenced to 75 years in prison for abusing DeAngelo. Ferreira testified against her at the trial. She appealed her conviction but the appeal was denied. Foul play is suspected in DeAngelo's case. Police believe Patricia may have harmed or killed him. She has not been charged with any wrongdoing in connection with his disappearance, however, and the child's case remains unsolved.

Some agencies classify DeAngelo's case as a non-family abduction.