Texas police say a 19-year-old man has admitted to strangling his pregnant older sister — and faking her suicide — out of embarrassment for their family.

Eduardo Arevalo is charged with capital murder in the death of his 23-year-old sister Viridiana Arevalo, who was about a month from her due date. Residents found the body of the soon-to-be mother in a neighborhood alley early Sunday, less than a mile from her family’s home in a Dallas suburb called the Colony. Her brother’s arrest came soon after.

“The only reason he gave for killing her was that she was an embarrassment to their family,” Colony Sgt. Aaron Woodard said during a news conference. “And he stated that it would be better off that she wasn’t here.”

Viridiana had been excited about having a baby girl, her brother Diego Arevalo told local station KTVT-TV, noting that she “always wanted a little sister.” But she disappeared from home on Dec. 16, with a family member claiming to police that she had “made some statements about harming herself because of some personal issues.”

She had reportedly struggled with mental health problems, and relatives found a suicide note.

Missing, and Possibly Endangered, Person On Tuesday, December 17, 2019 at 6:50pm, The Colony Police Department was...

Posted by The Colony Police Department on Wednesday, December 18, 2019

Police, however, were skeptical. Footage from cameras in the area where the body was found helped lead them to Eduardo Arevalo. They say he admitted the crime. “I murdered her … I murdered her,” he told detectives, according to a probable cause affidavit. He claimed he needed to “protect his family and the unborn child from its mother,” blaming the “ongoing conflict” his sister’s mental health condition caused in the family, the affidavit said.

The brutal killing unfolded on the morning of Dec. 16, after the siblings got into an argument, according to the affidavit. Eduardo went into his room and tried to go to sleep but thought to himself, “Maybe it’s time to murder her,” the affidavit said.

According to the affidavit: As Viridiana sat on a couch in the living room, Eduardo approached from behind and put his arm around her neck, squeezing until she stopped breathing. He wrapped her head in duct tape, the affidavit said, “because he was afraid that she might come back to life.”

Then, the affidavit said, he drove her body outside of the city and into Fannin County, leaving her in a grassy field where he believed she “would not be discovered.” And he wrote the supposed suicide note, Woodard said.

Six days later, during the early morning of Dec. 22, he allegedly retrieved his sister’s body and drove it back to the Colony. He left her corpse in the alley, police said. On his way home, he stopped at Whataburger to get something to eat.

After Viridiana’s body was found, investigators brought Eduardo in for an interview, believing that he might be involved in her death based on the evidence. He confessed while being questioned, police said, and provided details only the killer would know. He was handcuffed and arrested at the end of the interview.

The family is devastated by the situation, Diego Arevalo told KTVT-TV, adding that “seeing my parents sad and emotional really breaks my heart.” He said he didn’t believe his brother was the killer, despite the alleged confession.

“I know my brother,” he said. “He wouldn’t do something like this.”

As the family struggles to process the death of one sibling and arrest of the other, Eduardo Arevalo sits in the local jail. His bail is set at $1.05 million the Dallas Morning News reported. Police said additional charges could be filed against him.

Woodard told the Morning News that the case had been difficult for investigators.

“It’s not what our officers and detectives wanted to be dealing with two days before Christmas,” he said.

Read more: