Authorities in Texas say they've found a woman who was captured on video ringing a doorbell in the middle of the night, her wrists shackled in what appeared to be broken restraints.

Lt. Scott Spencer of the Montgomery County Sheriff's Office says the 32-year-old woman is safe with family out of state.

He also says deputies found her 49-year-old boyfriend dead Wednesday morning at a house in a subdivision 46 miles north of Houston. Spencer said he died of a single gunshot wound.

The boyfriend was identified as Dennis Ray Collins at a news conference on Thursday.

Investigators determined that his girlfriend was the barefoot young woman seen in a nearby resident's security video ringing the doorbell early Friday while wearing a T-shirt and wrist restraints.

Spencer said her identity is being withheld for now as a domestic violence victim.

Spencer said Thursday that police had received a call from a woman who said she had received concerning text messages from her ex-husband and believed he was going to hurt himself. She also said she believed the woman in the doorbell ringing video was her ex-husband's girlfriend.

Deputies tried to call Collins and knock on the door of his home but got no response, so they forced their way into the residence and found him "in the back bedroom with a self-inflicted gunshot wound," Spencer said.

Investigators then found evidence that his girlfriend was the woman from the video, including text messages from Collins to that woman explaining what happened, he said. They then located the woman's family members and eventually made contact with her.

The woman described the wrist restraints as those "commonly used in private, intimate encounters" and said she was the victim of a sexual assault, Spencer said.

"She was in distress, obviously the allegations are that she was tied up by Mr. Collins and so she went to seek help," he said.

She rang the bells of Collins' neighbors homes but when they didn't answer the door she went back to the home and shortly after drove away to Dallas, he said.

"Her allegations of sexual assault are being taken seriously and those are being investigated right now," he said.

"She's pretty upset, she's very distraught about this," he said.

"Mr. Collins used the restraints on her and after that she was able to break free," he said, but added investigators were still learning the alleged details of the incident and the investigation was still ongoing.

Spencer said that in notes found after Collins' death "he admitted that he did what he did to her that was seen in the video" and that Collins was aware of the video.