A 17-year-old boy killed New Year's Eve in Greencastle and the 15-year-old accused in the fatal shooting were identified at a Pennsylvania State Police press conference late Monday morning.

Matthew Mitchell was pronounced dead at the scene of the incident reported around 10 p.m. Saturday in Apartment D at 431 W. Baltimore St.

Taylor Nelson, who lives in the apartment, is charged as an adult with criminal homicide in Mitchell's death.

"It's unfortunate for all that are involved," said Pennsylvania State Police Cpl. Ryan Lawrence, who addressed the media for nearly 15 minutes in a conference room at state police barracks in Chambersburg.

Lawrence noted that the investigation is ongoing and the chance of more charges being filed "may be a possibility."

*** Fatal events ***

According to charging documents, Nelson was mad at Mitchell for picking on him and got a gun from his father's nightstand to "scare" him. At one point Nelson chambered a round to further scare Mitchell. Nelson then put the gun on the floor, picked it up about 10 minutes later, dropped the magazine out of the gun, pointed it at Mitchell's forehead and pulled the trigger one time, shooting him in the forehead, according to the affidavit of probable cause.

Nelson told police he "did not know the gun was loaded and did not intend to kill the victim," the documents said.

Lawrence said that the gun used was a semi-automatic pistol which was legally possessed at the residence, but not by Nelson. He did not reveal who owned the gun.

"Unfortunately incidents like this happen often and it shows that there should be responsible gun ownership and trainings to make these events less often," Lawrence said. "My advice to the public would be to always assume a gun is loaded."

State police said that the shooting took place on the first-floor basement of the residence and there was at least one adult in the home at the time. A 911 call from within the residence alerted police to the incident, but Lawrence was unable to reveal who made the call.

It is "unclear at this time" according to state police whether alcohol was involved in the incident. An autopsy on Mitchell will be conducted Tuesday morning, according to Franklin County Coroner Jeffrey Conner.

*** Homicide charges for a juvenile ***

According to Franklin County District Attorney Matt Fogal, criminal homicide in Pennsylvania is an umbrella charge. A judge or jury will ultimately decide whether a crime occurred and if it is first-, second-, or third-degree murder, voluntary manslaughter or involuntary manslaughter.

"Anytime homicide is charged, it has to be initialized by a criminal complaint in the adult court system," Fogal, who added that cases involving juveniles can be decertified back to the juvenile court system, but that would require the court to uphold a motion from the defense.

Magisterial District Judge Jody C. Eyer arraigned Nelson on a first-degree felony count and ordered him to be held in Franklin County Jail without bail. State police were unable to reveal whether Nelson was being held in the general population at the prison.

A preliminary hearing is scheduled for Jan. 10 in Franklin County Central Court.

The Greencastle Police Department asked state police to take over the investigation. Lawrence said it is standard procedure for some of the police departments in Franklin County to defer a homicide case to state police.

Contact Dustin Haluska at dhaluska@therecordherald.com, 717-762-2151 or on Twitter: @dhaluska