An argument outside a Planet Fitness in Westmoreland County led to a shooting on Tuesday, police said. 

One man is in custody, and another is in the hospital after the shooting at Crossroads Plaza in East Huntingdon Township, Pennsylvania State Police Trooper Steve Limani said.  

Three bystanders jumped in to provide medical aid, and it appears the victim will be OK, Limani said. 

"This guy is lucky to be alive," said witness Charles Tamblyn. "I don't think he would have been alive if it wasn't for the two nurses and the guy that helped, he was some kind of medic guy, plus everyone who joined in. That's the great thing, the community stepped up and helped." 

Steven Henry Tris Heald faces a list of charges, including criminal homicide and aggravated assault. He is due back in court later this month. Heald's bail was denied, and he remains in the Westmoreland County Jail. 

"I really want the public to know that right now there's no threat to the general public," Limani said. "The person that did the shooting is in custody. These two people were familiar with each other so it wasn't a random act of violence, and as the investigation unfolds, I'll be able to give you a lot more information." 

State police say there is no threat to the public, but the investigation is ongoing. They hope to have more information available on Wednesday.