An off-duty college campus police officer investigating why a car alarm was blaring outside his Metairie home shot a teenager in the head after a bright light on the boy’s cell phone suddenly flashed, something the officer mistook as a firing gun, the Jefferson Parish Sheriff’s Office said Wednesday.

The Sheriff’s Office said its detectives are still investigating the confrontation that led William Daniel Short to shoot a 14-year-old boy in Metairie last week. Short has not been booked with a crime, and sheriff’s investigators intend to consult with the Jefferson Parish District Attorney’s Office to determine whether he should face charges.

In the most detailed account of the shooting yet, the Sheriff’s Office said Short went outside his home in the 4800 block of Grammar Avenue about 3:10 a.m. on April 17 because a car alarm was going off. He feared there may have been "criminal activity" occurring, so he grabbed a gun, headed outside, and ordered three people he saw to stop where they were.

14-year-old boy shot in head by off-duty police officer in Metairie early Friday morning: JPSO An off-duty police officer shot a 14-year-old boy in the head during an encounter with several juveniles he found in the front yard of his Met…

Two immediately ran off, but the third — who had an object in his hand — remained, the Sheriff’s Office said. Deputies later learned that object was the boy’s cell phone, which had a feature that made a bright light shine when a call came in. The Sheriff’s Office said it has confirmed the boy’s phone received an incoming call around that time.

According to the Sheriff’s Office, Short saw what he believed to be a muzzle flash coming from the object in the boy’s hand, which he feared was a gun. Short fired once, and the bullet hit the boy in the head, the Sheriff’s Office said.

The Sheriff’s Office said Short realized the boy was holding a cell phone after he approached him. Short gave the boy CPR, and another resident of his home called 911. First responders took the boy — whose name hasn’t been released — to the hospital. An update on his condition wasn't available, but he remained hospitalized Wednesday, the Sheriff's Office said.

Deputies later found other minors who had accompanied the wounded boy. The Sheriff’s Office said they admitted their group of five had snuck out of their homes and were “joyriding” in a car that belonged to one of their parents. They parked the car near Short’s home while the group dropped off a friend who lived close by.

Two from the group got out of the car, and three stayed behind, with the vehicle's alarm activated, the Sheriff’s Office said. The three who had stayed back then climbed out of the car, tripping the vehicle's alarm.

Those three minors were walking away from the vehicle and near Short’s home when he encountered them.

Short and the teen are both white.

While the case remains unresolved, it could potentially be a test of Louisiana’s “stand your ground” law, which enables people to use lethal force against anyone who they reasonably believe could badly harm them.

Short works as an officer with Southern University at New Orleans’ campus police force. Short is on paid administrative leave pending the results of the law enforcement investigation into the shooting, the university said.

Previously, Short spent 14 years with the Orleans Parish Sheriff’s Office, attaining the rank of captain before he was fired in September 2017 following a failed drug test.

Short later filed a lawsuit seeking to be reinstated, alleging that the drug test gave a false positive for oxycodone and methamphetamine. U.S. District Judge Carl Barbier ultimately ruled against Short and dismissed his suit, and an appellate court has since upheld the decision, records show.

Note: This story was updated to clarify the car alarm that was going off.