Background: The 6300 block of Parkdale Drive in Dallas, Texas (Google Maps). Inset: Jose Magareno (Dallas County Sheriff”s Department).

A man accused of shooting his cousin to death in Texas allegedly said the incident occurred because he wanted to test his family member’s reaction time.

Jose Magareno, 21, is in the Dallas County Detention Center on a charge of murder, court records show.

The incident is said to have occurred on Monday at about 5 p.m., when 19-year-old Emmanuel Najera and his younger brother arrived at Magareno’s house to celebrate Najera’s birthday, according to an arrest affidavit obtained by The Dallas Morning News. When the topic of guns and concealed carry came up in conversation, they apparently went to Magareno’s room.

According to local Fox affiliate KDFW, Magareno gave Najera a gun, saying he wanted to “test his reaction time.” He reportedly told police that he had attempted to remove the rounds from his own gun.

Magareno is believed to have shot his younger cousin, as he reportedly called 911 and told the operator he had “accidentally” shot Najera in the chest. Dallas Police Department officers responded to the 6300 block of Parkdale Drive in Dallas, where Najera was transported to a local hospital, the department said in a press release. He later died.

The suspect was arrested, and as he spoke with officers, he apparently provided more details about how the alleged accident occurred. Magareno reportedly said he often practiced with his gun and believed he had taken out all the bullets from the gun before pulling the trigger.

Hours later, early Tuesday morning, he was booked into jail and charged with murder. The case was still being investigated as of Tuesday.