LONG BRANCH, N.J. — A 16-year-old is accused of killing his parents, sister and a family friend inside his parents' home on New Year's Eve, officials said Monday.
The teen is in custody and charged with four counts of murder and possession of a weapon for an unlawful purpose, Monmouth County Prosecutor Christopher J. Gramiccioni said. Authorities had not made a decision Monday on whether to charge the youth as an adult because of the seriousness of the offense; USA TODAY generally does not identify juvenile offenders until they face adult charges.

Police found the suspect's father, Steven Kologi, 44; mother, Linda Kologi, 42; sister, Brittany Kologi, 18; and family acquaintance, Mary Schultz, 70, minutes after a 911 call reporting shots fired. All four died at the scene.
The teen's grandfather and brother were able to escape the house unharmed, Gramiccioni said.
Investigators now are trying to piece together a motive for the mass killing, the prosecutor said. Dispatchers received the emergency call at 11:43 p.m. ET Sunday from within the home about 30 miles south of New York City.
"I could never have believed this could have happened. They were all good people," said Carmen Gaudious, a family friend from West Long Branch, N.J. "I just spoke to Steve (the father) three days ago. He looked good. It was cold, so we didn't say much. He wished me happy holidays."
A neighbor said he heard gunshots and fireworks from two different locations in the neighborhood almost simultaneously.
"I walked outside at midnight. We heard the commotion and lights flashing and saw (the police) storm the house," said James Roskowinski, referring to himself and a roommate.
Though he lives on the same street as the family, he did not know them, he said.
"It's a shame the new year has to start off like this," Roskowinski said.
The 16-year-old did not attend Long Branch High School, Superintendent Michael Salvatore said.
Family friends say the youth was homeschooled because of social and developmental disabilities.
Steven Kologi Sr. declared bankruptcy in 2009, according to paperwork filed in federal Bankruptcy Court in Newark. Eight years ago he said he was a mail handler with the U.S. Postal Service and had more than $420,000 in assets but almost $470,000 in liabilities; Linda Kologi was unemployed at the time.
The suspect used a Century Arms semi-automatic rifle to shoot his victims and reportedly was taken into custody without incident, Gramiccioni said.
"The weapon was legally owned and registered to a family member," the prosecutor said. The teen is expected to make his first appearance before a judge Tuesday.