Updated 5:30 p.m.: Revised to include additional information from family.

A Texas 17-year-old has been charged in the shooting death Sunday morning of his girlfriend, who had recently celebrated her 15th birthday.

Javon Martin (Harris County Sheriff's Office)

Javon Martin had a rifle and pointed it at Makaila Simon about 1:30 a.m. at a home in Spring, near Houston, Harris County Sheriff Ed Gonzalez said. Makaila was hit once in the chest, police said.

The high school freshman died at the scene, Gonzalez said. Family told KPRC-TV that she had just celebrated her 15th birthday and that the couple had been fighting over cheating allegations.

Martin faces a criminal negligent homicide charge, but Gonzalez said investigators are working to determine if the shooting was intentional.

A video that Makaila reportedly recorded moments before her death shows Martin waving a rifle with his finger on the trigger as she laughs and tells him to stop.

ONLY ON 2: One of Makaila Simon’s last recordings. You can hear the 15-year-old asking Javon Martin, 17, to stop pointing the rifle at her. This was recorded minutes before Makaila was fatally shot in her chest. Martin faces a criminal negligent homicide charge. @KPRC2 pic.twitter.com/zsBW0JEgbL — Taisha Walker (@KPRC2Taisha) January 27, 2019

"We don't know if it was accidental in terms of just playing [with] the weapon and the gun went off or if there was other intent," Gonzalez said.

Martin was indicted in a July on a felony unauthorized use of a vehicle charge and was set to stand trial in June, court records show.