SANTA FE, N.M. – Authorities say a man accused of killing a 13-year-old boy who endured years of abuse is dead as a result of what appears to have been a suicide at the Santa Fe County jail.

District Attorney Marco Serna said 42-year-old Thomas Wayne Ferguson was found dead in custody Saturday morning. He was awaiting trial on murder and other charges in the January death of Jeremiah Valencia.

County Sheriff Robert Garcia said it was his understanding that jail staff discovered Ferguson had hung himself, the Santa Fe New Mexican reported .

“We don’t suspect anything other than suicide by hanging,” Garcia said.

Serna said his office will “continue to aggressively prosecute” the co-defendants. They are the boy’s mother, Tracy Ann Pena, 35; and Ferguson’s son Jordan Anthony Nunez, 19.

“I am angry this happened,” Serna said of Ferguson’s death. “I don’t believe Ferguson is going to receive the whole justice my office was going to bring against him, to bring justice to Jeremiah, the family and the people of northern New Mexico.”

Police said Ferguson brutally beat the Nambe teen to death while Pena was in jail on a warrant for failing to appear in court. The boy’s body was found buried along a rural highway.

Authorities did not discover his body until two months after his estimated death in November because no one reported Valencia as missing.

All three are jailed on suspicion of child abuse resulting in death, tampering with evidence and conspiracy to commit tampering with evidence.

Ferguson told investigators that Valencia died after he and Nunez had been roughhousing, according to court documents. However, Nunez said he saw his father punching the boy in the face and stomach multiple times on Nov. 26. Nunez said the boy was bleeding and that Ferguson put padlocks on all the doors in the house to make sure no one left.

Pena told investigators that when she got out of jail on Nov. 26, she went home to find her son’s body wrapped in a blanket. After confronting Ferguson, she said he put the body in a vehicle and drove away.

She told authorities she was scared of Ferguson and that he had physically abused the boy in the past. She said Ferguson later took her to a spot where the boy was buried, a location she shared with authorities.

Authorities say the family was able to conceal the boy’s death because he was not enrolled in school and had never been reported missing.

The investigation began when authorities received confidential information about a possible homicide from an inmate who was in jail with Pena. The inmate told authorities Pena had talked about finding her son dead and blamed Ferguson, who also was in jail at the time on a probation violation.

Authorities said Nunez, who is also identified in court documents as Jordan Munoz, reported growing up in a “very abusive environment” and that another child who was at the home was placed in the custody of child protective services.