It was all in fun. But now a local man is dead and his friend faces murder charges. It’s a bizarre story where joking around turned fatal. 36-year-old Juan Pablo Alaniz may spend up to 20 years in prison for unintentionally killing his friend while horse playing.

Saturday night was the last time 39-year-old Alfonso Matos would spend time with family and friends. Matos and Alaniz played rough frequently. They would fight each other for fun, but they had rules: no punching in the face and no kicking.

“They did it often. It was something that they would do. They’d fight each other and punch each other and this time it had tragic consequences.”

And tragic it was, at an abandoned convenience store located at the 800 block of west Elizabeth street in Brownsville, Matos and Alaniz had their last play fight. In front of friends, they fought. Alaniz threw several punches to Matos' rib area. The punches were strong enough they broke one of Mato's ribs and ruptured his spleen.

“He was having a hard time breathing. At one point he started going into convulsions and they took him to the hospital and when he got there, he died.”

Autopsy results show Matos bled to death due to that ruptured spleen.

“Unfortunately this is what happens when you engage in dangerous conducts. Somebody gets hurt.”

Brownsville Police Sergeant, Jimmy Manrrique says he has seen a trend of this play fighting usually with teens. Teenagers will fight and post the act on the internet.

“Now this has happened, where there needs to be that message needs to be received by these young kids that although you're engaging in horse playing if somebody gets hurt to this degree somebody is going to be held accountable.”

And that is exactly what has happened to Alaniz. Although Matos agreed to fight, Alaniz has been charged with manslaughter.

Alaniz is being held at the Cameron county jail with a second degree felony. He’s being held on a $75,000 bond.