Jose Magareno, a Dallas, Texas man, shoots his cousin, Emmanuel Najera, killing him while testing his reaction time

A Dallas, Texas man admitted to shooting his young cousin dead, telling authorities he wanted to 'test his response time' after the subject of weapons came up.

Jose Magareno, 21, and 19-year-old Emmanuel Najera, along with his younger brother, arrived at the suspect's home on Monday afternoon about 5.15 p.m. to celebrate Magareno's birthday.

When the topic of weapons came up, the group moved to Magareno's room and began practicing concealed carry when Magareno urged Najera to test his'reaction time,' according to an arrest document obtained by the Dallas Morning News.

Maganero had given Nanjera a gun before the shooting, only to draw a loaded pistol and shoot Najera in the chest, the affidavit stated.

Magareno contacted 911, claiming he had 'accidentally' shot Najera in the chest. According to a news release from the Dallas Police Department, officers rushed to the 6300 block of Parkdale Drive in Dallas and took Najera to a local hospital. He later died.

During police questioning, Magareno stated that he frequently practiced with his revolver and believed he had removed all of the bullets before pointing it at his cousin and pressing the trigger.

Magareno was booked into the Dallas County Jail on murder charges. As of Wednesday, his bond had not been set, according to jail records.

The police investigation into the shooting is ongoing.