Father accused of fatally beating man who tried to enter bathroom occupied by teen daughter

A 40-year-old father in Arizona has been charged with second-degree murder after cops say he fatally beat a man who tried to enter a bathroom occupied by his teen daughter.

Melvin Harris was picking up his 16-year-old daughter and two of her friends earlier this month when they asked to stop at a convenience store, his fiancee Diana Jackson tells AzFamily.com.

When the teen was in the bathroom at the QuikTrip store in Phoenix, a man identified by Azfamily.com as Leon Leevon Armstrong tried to get inside her locked stall.

She told an employee about the incident, and a security guard was told as well.

Harris told the security guard he needed to "handle the situation," according to cops, "or he would do it himself."

"If you know there's a known problem, why not fix it before it got that far?" Jackson told AzFamily.com.

The security guard told Harris he would take care of it. However, cops say that Harris got back into his vehicle and pulled it into a gravel area near where Armstrong was. Harris is accused of punching Armstrong in the face, and he allegedly hit him repeatedly while the victim was on the ground.

Armstrong suffered swelling to the brain and had a nasal fracture. Armstrong died from his injuries.

Harris claimed that Armstrong threw a punch at him first, according to Azfamily.com.

"I would have done the same thing," fiancee Diana Jackson told Azfamily.com. "I don't feel bad at all for his actions. I feel bad that the man ended up dying in the process. I do."

Jackson said she has not seen Harris in 11 days since the arrest.

"But now he's a criminal for protecting his child? That's not fair. It's not," she tells the news website.