4 suspects arrested in mass shooting that erupted in New Mexico park

Four suspects, including two 17-year-old boys and a 15-year-old boy, have been arrested and charged with multiple counts of murder stemming from a mass shooting that left three teenagers dead and 15 other people injured at an unsanctioned car show at a park in Las Cruces, New Mexico, police said Sunday.

The deceased are a 19-year-old man, an 18-year-old man and a 16-year-old boy, police said. The injured victims range in age from 16 to 36, the Las Cruces Police Department said in a statement to ABC News.

The shooting unfolded around 10 p.m. local time on Friday in Young Park, the Las Cruces Police Department said.

"Officers arrived and learned of multiple gunshot victims. Most were transported to local hospitals. Some were taken to University Medical Center of El Paso," police said.

Police announced early Sunday on social media that they had arrested Tomas Rivas, 20, and a 17-year-old boy in connection with the shooting. On Sunday afternoon, police announced the arrest of the third and fourth suspects, another 17-year-old boy and a 15-year-old boy.

Rivas and the three juveniles, whose names were not released, were all charged with three open counts of murder, police said. Additional charges against the suspects are pending, according to police.

The victims killed in the shooting were identified by police as Andrew Madrid, 16; Jason Gomez, 18, and Dominick Estrada, 19. Madrid and Gomez, according to police, died on the scene. Estrada was taken to MountainView Regional Medical Center in Las Cruces, where he was pronounced dead, according to police.

During a news conference Saturday, Las Cruces officials said an unsanctioned car show was being held at the park before the shooting, and there was an altercation between two groups of people that led to an exchange of gunfire.

Nine men and six women were hit in the crossfire and suffered gunshot wounds, police said. Seven of the victims were taken to hospitals in El Paso, while the remainder were treated at hospitals in Las Cruces, police said. Their names were not being withheld to protect their privacy, according to police.

Shaquane Heckstall, 27, a team captain of an El Paso-based car club, told ABC News that he was at the park for the car show when the shooting broke out. He said his training from his 8-year career as an active duty solider in the Army kicked in when he heard the gunshots.

“I heard the pops going off, and I’m thinking it's someone's car, like their exhaust backfiring," Heckstall said. "But then once it didn’t stop and then people started running, I was like: That’s not what that’s supposed to be."

He said he rushed to help victims, grabbing whatever he could use as makeshift tourniquets or to apply pressure to wounds: shoelaces, two T-shirts and a pair of sweatpants.

"Once the gunfire stopped I’m looking around, I see the bodies on the ground," Heckstall said.

Heckstall said he rendered aid to a teenager who was crying to him to "go help my dad."

“At this point, I'm just trying to make sure he stays awake and keep him talking to make sure that he's still good, you know?" Heckstall said of the wounded teen victim. "I take one of the T-shirts to try and bandage some of the wounds, and then he stops me. He's like, bro, go help my dad."

The Las Cruces Police Department said it is receiving assistance on the investigation from the FBI, the New Mexico State Police, Dona Ana County Sheriff's Office and the federal Bureau of Alcohol, Tobacco, Firearms and Explosives.

ABC News' Erica Morris, Melissa Adan and Tristan Maglunog contributed to this report.