FARMINGTON — A man who admitted to sexually assaulting his stepsister when he was a juvenile now faces criminal sexual penetration charges involving the same girl.

Matthew Black, 19, is charged with five first-degree felony counts against a minor under 13 years old. He allegedly had sex with his 12-year-old stepsister five times between October 2012 and January.

Black was booked into the San Juan County Adult Detention Center last week. He is being held on a $500,000 cash-only bond set by Magistrate Judge Trudy Reed-Chase, according to court documents.

Black is scheduled to have a preliminary hearing this afternoon.

The San Juan County Sheriff's Office started investigating Black in January when the victim's mother told deputies that Black had sex with his stepsister at the family's home near Aztec, according to the affidavit for his arrest.

Black was staying in a separate building on the family's property, said Detective Ken Weisheit.

Investigators found incriminating text messages between Black and his family members. In the messages, Black said he wouldn't see or talk to the girl anymore, according to the affidavit. He also said he was leaving the state and never coming back.

"I WONT TLK TO HER TELL SHES 18!," he texted, according to the affidavit.


In an interview with investigators in February, the victim said that she had sex with Black five times between October 2012 and January, according to court documents.

A warrant for Black's arrest was issued March 7, but Black had already left the state, Weisheit said.

One of Black's relatives said that after family members confronted Black about the sexual abuse, he went to live with his mother in Oklahoma.

Weisheit said that Black broke his cell phone so that investigators couldn't find or talk to him. U.S. Marshals arrested him last month.

In September 2010, Black was charged with criminal sexual penetration against a child and criminal sexual contact against a child for molesting his stepsister, according to court documents. As part of a plea agreement, he pleaded guilty to lesser charges of aggravated battery and aggravated stalking. During his explanation for accepting the plea, Black admitted to and described a sex crime against his stepsister, according to court documents.

He was sentenced to two years of supervised probation, community service and counseling and was ordered not to have any contact with the victim.

A document filed in district court in late November — more than a month after Black allegedly had sex with his stepsister for the first time — said Black had successfully completed his probation.

Weisheit said Black, his father and stepmother had an agreement that allowed Black to live in a separate building, away from his stepsister, on the family's property.

Ryan Boetel can be reached at; 505-564-4644. Follow him on Twitter @rboetel