LONG BRANCH, N.J. (CBS) — Police have arrested a 16-year-old boy who they say shot and killed his parents, sister and a family friend inside a home in the New Jersey shore town of Long Branch, Monmouth County.

Police were called to the scene around 11:45 p.m. Sunday in the 600 block of Wall Street, where they discovered the bodies of four people.

The Monmouth County Prosecutor’s Office identified the victims as the teen’s parents, Steven and Linda Kologi, 44 and 42 respectively, his 18-year-old sister, Brittany, and 70-year-old Mary Schultz, who lived with the family.

Authorities said it appeared the teen used a semi-automatic rifle in what they described as an isolated domestic incident.

He was taken into custody without incident.

Authorities said the teen’s grandfather and brother were not targeted and left the home unharmed.

Charges were expected to be filed later Monday.