Brown County Sheriff’s investigators have been unable to substantiate an 18-year-old man’s claim that he was sexually assaulted in a jail cell by other male inmates on April 9, Sheriff Bobby Grubbs said.

Texas Ranger Steve Boyd has participated in the investigation, which began after sheriff’s officials learned of the man’s allegation on April 12, Grubbs said.

Investigators are “having problems” related to the amount of cooperation they are getting from the alleged victim, and that is hindering the investigation, Grubbs said.

“At this point we have been unable to substantiate that this actually occurred,” Grubbs said. “We are continuing an investigation. At this point we can’t really say completely that it didn’t happen, but we have not been able to gather the evidence to substantiate the offense.

“We have not received complete cooperation from the victim.”

Brownwood police arrested the man on April 2 on traffic charges and on a warrant for failure to appear in court on a weapons charge, Grubbs said. He was released from jail on April 12 after speaking with deputy Michelle Holder about the alleged assault.

A jailer told Holder on April 12 that a bail bondsman had contacted her and was inquiring about the inmate’s bond, and then asked about the inmate being assaulted and placed back in the cell with the suspects.

The jailer said it was the first she had heard of this so the inmate was pulled out of his cell and asked about what had happened, Holder’s report states. The jailer placed the inmate in a holding cell by himself and called for a deputy.

The jailer wrote up an incident report and printed off the inmate list of who was in the cell.

The inmate said he and another inmate had a confrontation on April 9 that started out verbal and turned physical. The inmate said the other inmate told him something bad was going to happen, Holder’s report states.

The inmate said about 1 1/2 hours later, after lights out — around midnight on April 9 — he was held down and sexually assaulted by more than one person. He told the deputy he blacked out and wasn’t sure how many people assaulted him.

Holder asked the inmate why he did not tell jailers. The inmate said other inmates had threatened to kill him after the assault.

The inmate told Holder he told his mother at visitation and she was the only person he told until sheriff’s officials asked him about it.

Grubbs said there were six to eight inmates in the inmate’s cell and investigators have taken statement from them. He declined to elaborate.

Investigator Lana Guthrie said investigators have asked the alleged victim to provide DNA evidence “to allow us to move forward with this case.”

“There is no physical or DNA evidence at this time,” Guthrie said.