Collin County jury sentences man to 50 years for abusing disabled teen

A Collin County jury sent Marty Duwayne Griego, 52, to prison for 50 years without parole after convicting him of continuous sexual abuse of a disabled individual in a case prosecutors said involved a severely autistic 15-year-old girl and stretched across about a year. The punishment, announced May 5 after an April 22 conviction, means Griego will not be eligible for release through parole under Texas law.

Prosecutors said the case was pursued aggressively because the abuse was not a one-time assault but a pattern that unfolded in multiple places, including Plano, Carrollton and Corpus Christi. They said Griego used an ongoing relationship with the girl’s family to gain access to her, a detail that made the case especially serious for child abuse investigators and for jurors weighing how a disabled teenager could be targeted over time.

Evidence at trial included DNA and testimony from a child witness, and jurors also heard evidence involving additional victims. One report said the abuse came to light after Griego assaulted the girl in front of another child, who immediately reported it. Plano police Detective Catherine Foreman led the investigation, and the victim described the abuse in a forensic interview at the Children’s Advocacy Center of Collin County, where child victims are often interviewed in a setting designed to reduce further trauma.

Collin County District Attorney Greg Willis said Griego was a “serial predator” and that the sentence ensured he would never walk free again. The 50-year no-parole term signals how Collin County is treating long-running sexual abuse cases involving disabled children: as public-safety cases meant not only to punish one offender, but to protect other vulnerable children from similar grooming and exploitation. At the end of the sentence, one local report noted, Griego would be 102 if he lived that long.

For families of disabled children, this case is a reminder to watch for adults who insist on unusual access, push for secrecy, or spend time alone with a child across more than one setting. Concerns can be reported to the Plano Police Department, the Children’s Advocacy Center of Collin County or the Collin County District Attorney’s Office, all of which play a role in identifying and prosecuting abuse cases in the county.