The preppy Princeton, New Jersey man who allegedly killed his younger brother in the family’s upscale apartment also set the family cat on fire during the attack, a law enforcement source tells The Post.

A Princeton man has been charged with killing his brother and a pet cat in an apartment Saturday night, authorities announced Monday. Matthew Hertgen, 31, is charged with first-degree murder and related weapon possession charges in the death of Joseph Hertgen, 26, the Mercer County Prosecutor’s Office said in a statement.

A former college soccer player is accused of killing his younger brother and a cat, New Jersey prosecutors announced Monday, Feb. 24. The Mercer County Prosecutor’s Office said charges have been filed against Matthew Hertgen, 31, for first-degree murder and weapons offenses in connection with the death of his 26-year-old brother, Joseph Hertgen.

The preppy Princeton, New Jersey man who allegedly murdered his younger brother and butchered the family feline inside their luxury apartment posed with an $8 cat toy the day before the gruesome killings.

New Jersey authorities have arrested Princeton man Matthew Hertgen, who is accused of killing his brother, Joseph Hertgen, and a cat, allegedly with a knife and golf club.

A New Jersey man has been charged with first-degree murder in the death of his brother, who was a former University of Michigan soccer player.

A former college soccer star from Princeton, New Jersey, has been charged with murdering his own little brother — and a pet cat — over the weekend in an apartment near the campus of Princeton University.

A former college soccer star from Princeton, New Jersey is charged with murdering his younger brother. “Through the death of a very old Pontiff… a Roman of good age will be elected." Rep. Andy Ogles (R-Tenn.

Matthew Hertgen, who is a former Wesleyan student and soccer player, was charged with first-degree murder in the death of his brother, officials said.