EDINBURG — After about an hour of deliberations, the jury found a 34-year-old Mercedes man guilty of fatally stabbing a teen in late 2020.

The Mercedes Police Department arrested Fidencio Castillo Cosme on Sept. 28, 2020, hours after he attacked 16-year-old Armando Torres IV from behind and stabbed him in the chest.

Fidencio’s brother, 37-year-old Juan Jose Cosme, was also accused of participating in the stabbing, and he was arrested that same day and charged with murder.

He has pleaded not guilty and is awaiting trial.

The jury’s decision follows five days of evidence and witness testimony that prosecutors used to show Fidencio was angry because he believed Torres and some other neighborhood kids were casing his mother’s house for a robbery.

However, in closings, Hidalgo County Assistant District Attorney Vance Gonzales said there is no evidence that anyone tried to steal from Fidencio and that the 34-year-old man just told that to police because he was trying to justify what he did.

One of the teens in the alleyway that night also testified that he and Torres, his best friend, were hiding in the alleyway because they were out at 1 a.m., which violated the then pandemic curfew for minors, and had seen police.

A confrontation ensued between Fidencio and Juan, who had a machete, and they chased the teens away from the residence.

Either the next day or a few days later — it wasn’t clear because of varying testimony — Fidencio saw Torres, who was wearing headphones, walking past his house at about 1 p.m. on Sept. 28, 2020.

Torres was walking to his best friend’s house.

That’s when the brothers attacked Torres from behind, with Juan placing him in a headlock while Fidencio stabbed him, prosecutors said. The attack caused a 4-inch deep wound to his chest and punctured the teen’s sternum.

“In front of people in broad daylight at one o’ clock. What a shame,” Gonzales said.

As for Fidencio’s concerns for his mother and the alleged threat of a break-in, Gonzales said that’s just an excuse for his actions.

“The only thing Fidencio Cosme care about is himself, his mother and some kittens,” the prosecutor said.

After his arrest, Fidencio described to Mercedes police what he did when he saw Torres walking past his house.

“I go back to my room. I grab something and go f—— stab him,” Fidencio said.

The jury watched this confession right before it went to deliberate and Gonzales, who prosecuted the case with Assistant District Attorney Jay Garza, stressed the video to the jury in the second half of the state’s closing.

“It’s so senseless and dumb,” Gonzales said.

He called it a brutal and gruesome murder and that Fidencio had no defense.

“Bad kid defense; y’all aren’t going to buy that,” Gonzales told the jury. “He’s a kid and he murdered him without mercy and without remorse.”

Fidencio’s defense had sought to portray Torres as a juvenile delinquent who was a problem in the neighborhood. His attorneys also attacked the Mercedes Police Department’s investigation as not being thorough and full of missteps while arguing police there failed to address the Cosme’s complaints about people allegedly casing their house for a robbery.

Gonzales told the jury they should ignore his defense because he doesn’t have one and that the case is a common sense case and that Fidencio has no excuse or justification.

“He took the law into his own hands and expects you to exonerate him right now,” the prosecutor said.

He said their deliberations shouldn’t take more than 30 minutes.

“Show him the same mercy he showed Armando Torres,” Gonzales said.

Fidencio is scheduled for sentencing Thursday morning.