A 15-year-old Georgia girl was discovered by her mom lying in bed with an apparent gunshot to the head – and three 18-year-old men described as acquaintances have been charged with her murder.

Madison Gesswein’s mom called 911 early Tuesday after making the horrific discovery in their apartment at The Greens at Braelinn in Peachtree City, telling the dispatcher that her daughter was “bleeding from the head,” 11Alive reported.

She said that when she entered her daughter’s bedroom, the window was open and the blinds were “a mess.”

The unidentified mom told the dispatcher that she “can’t get any response from her,” but that “there’s a lot of blood” on the bed and that her son was asleep in his room.

The dispatcher then instructed the mom how to administer CPR to her daughter and counted the beats until first responders arrived nearly five minutes later.

On Wednesday, police arrested three 18-year-old suspects they described as Madison “acquaintances.”

Justus Smith, Jacobean Brown and Yeshua Mathis, all of Fayetteville, Georgia, were each charged with murder, Peachtree City police said in a statement.

“A final cause of death is pending determination by the medical examiner, but an injury to Madison’s head appears consistent with a gunshot wound,” police said.

A motive for the shocking crime has not been determined yet.

“This was not a random act,” Assistant Police Chief Matt Myers said, Fox 5 Atlanta reported. “They knew whose apartment they were at, and it was in some way related to matters between these individuals.”

Jada Zimbabwe, one of Madison’s friends, remembered the young girl as “just really sweet,” telling the news outlet that “everyone I know liked her.”

The pal added: “It’s just so scary knowing someone so close was murdered, so brutally.”