LAS VEGAS (KLAS) — An 18-year-old man was arrested in Henderson Friday for allegedly killing his girlfriend. According to Henderson Police, Noah Hadley shot and killed 19-year-old girlfriend.

Investigators say the woman, whose identity was not released, was shot late Thursday night in the area of Horizon Ridge Parkway and Paradise Hills drive.

Residents who live in the gated community say they were shocked by the sound of gunfire, but they reacted quickly and tried their best to save the teen woman’s life.

“Eleven at night, and all of a sudden the world comes apart, neighbor Tom Neil said. “It’s a tragedy to have this happen in front of your house.”

Tom Neill was startled by the sound of what he thought were fireworks, at first.

“I laid there and heard voices: A lot of yelling, screaming; I went to my front door, and I could see the victim on the ground on her back,” Neil said. “People were trying to administer CPR to her.”

One of those neighbors who was quick to jump in says before police arrived, he saw the woman on the ground with people around her, including Hadley.

“I asked what was going on; he said she was shot,” one neighbor said. “They didn’t know CPR. My girlfriend, she knows CPR because she just graduated from nursing school, so we tried to help.

He says the woman didn’t live in the Horizon Heights community, but that the man accused of killing her, did in this home, across a parking lot.

“There’s always young kids over there,” the neighbor said. “He said something about they were having a party, and she was leaving the party. The mother showed up, and she was here crying. It was unfortunate to see a girl like that. She was only 19 to lose her life it’s a shame.”

Hadley is charged with one count of murder with a deadly weapon.