Princeton suspect in court for brother’s gruesome murder The Princeton, New Jersey, man accused of killing his brother and a family cat is set to appear in court for the first time Thursday. Matthew Hertgen,

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.

The Princeton, New Jersey, man known as a star student in high school who is now accused of killing his brother likely had a mental breakdown, an expert said.