Teen arrested in gun death at sports field

Police have arrested a 16-year-old Kent boy suspected in the fatal shooting of a man outside a Federal Way youth football practice last week. Luis Cosgaya-Alvarez was booked into the King County Jail on Monday and charged with second-degree murder in connection with the slaying of Omero Mendez. He is being charged as an adult.

According to Federal Way police, Cosgaya-Alvarez shot Mendez, 26, in the face after a dispute in the parking lot at Lakota Middle School on Thursday night. Mendez argued with Cosgaya-Alvarez and two men in a Lincoln Navigator for blocking his vehicle, according to charging papers filed in King County Superior Court.

Cosgaya-Alvarez pulled a blue bandanna across his face and opened fire, court papers said. A friend of Mendez's told police that he chased after the Navigator as it was driven away, but when Cosgaya-Alvarez pointed a gun at him he backed down, court papers said.

Mendez was at the school picking up a friend's little brother from his junior-league football practice when he was shot, court papers said. About 20 people witnessed the 8:20 p.m. shooting, police said.

A tip led Federal Way and Seattle police on Monday to a house near 12th Avenue Southwest and Southwest Myrtle Street in Southwest Seattle, where Cosgaya-Alvarez was arrested for investigation of murder, said Federal Way police spokeswoman Cathy Schrock.

Cosgaya-Alvarez left a message with Federal Way police over the weekend to say that he wanted investigators to contact his father, charging papers said. The father told detectives that his son claimed that he shot Mendez out of fear after the victim shot at the Lincoln Navigator. Police said there was no indication that gunfire was exchanged.

The King County Medical Examiner's Office said Monday that Mendez died of a gunshot wound to the head.

While Schrock said that the shooting isn't believed to have "any direct connection to gang affiliations," witnesses to the shooting said that Cosgaya-Alvarez flashed gang signs and exposed forearm tattoos before shooting Mendez.

Cosgaya-Alvarez, who goes by the nicknames "Youngster" and "Junior," has been arrested over the past year for allegedly assaulting a police officer and possession of a firearm. He has no criminal convictions.

Prosecutors had issued an arrest warrant for Cosgaya-Alvarez last week, Schrock said.

Jennifer Sullivan: 206-464-8294 or jensullivan@seattletimes.com