BROOMFIELD, Colo. -- The family of a man stabbed to death at a Broomfield bar over the weekend says they are afraid he was killed because he was gay.

Matias Mondragon, 31, died early Sunday morning after being stabbed in a fight outside the Night Owl Lounge, police said.

Monday investigators arrested Matt Joe Weber, 31, of Arvada on a first-degree murder charge, said Scott Swenson, spokesman for the Broomfield Police Department.

According to the arrest affidavit, Weber confessed to stabbing Mondragon.

Mondragon's niece, Angel Mondragon, told the Daily Camera her family is concerned Mondragon was killed because of his sexual orientation. She said the family has heard stories about the incident saying he was harassed at the bar because he was gay.

"We don't really know what happened to him," she told the Camera. "All we know is he got stabbed and he is dead."

Matias Mondragon recently moved to Colorado from New Mexico to be with a new partner, Angel Mondragon said.

A spokeswoman for the district attorney's office said prosecutors have not yet determined if the stabbing can be considered a hate crime.

According to the arrest affidavit, Weber told police he got into a verbal fight with Matias Mondragon and used a gay slur against Weber and his friends.

Weber said he "flipped (Mondragon) off" before he and friends left the Night Owl.

Mondragon followed them outside, and there was a fight in the parking lot at about 1:45 a.m., the affidavit said. Mondragon was stabbed and later died at the hospital.

Weber fled but called police a few hours later to turn himself in.