A 19-year-old in Tennessee is dead after her boyfriend accidentally shot her in the stomach while attempting to show her a new gun he recently got as a graduation gift, according to multiple reports.

Police said Brennan Fields, 18, allegedly fatally shot Lucinda Luna at around 11:30 p.m. on Thursday in Arlington with a .45 caliber pistol he had gotten as a gift from Luna’s father, according to The Commercial Appeal. She died later at a Memphis hospital.

“It’s just a real tragedy,” Shelby County Sheriff’s Office spokesman Earle Farrell, told the Appeal. Farrell noted that Fields would not face charges in the shooting.

Witnesses told authorities that Fields was putting the gun away when it went off and struck Luna, WREG reports.

“I didn’t think it was real,” Luna’s friend Karalyn Stubblefield told the station of the shooting. “I thought it was a joke or someone was messing with me. I didn’t believe it at all.”

Stubblefield described Luna as “really funny” and “amazingly smart.”

“She was always smiling, giggling and happy,” she told WREG. “She was a good girl.”

Detectives told the station that Luna’s father took Fields to a local shop to pick out the gun for himself.

Luna was laying on a couch across the room from Fields when the gun went off, according to FOX 13. Two other people and a toddler were reportedly in the room at the time.

Officials with the Shelby County Sheriff’s Office did not immediately respond to a request for comment from PEOPLE.

• Want to keep up with the latest crime coverage? Click here to get breaking crime news, ongoing trial coverage and details of intriguing unsolved cases in the True Crime Newsletter.