The Princeton, New Jersey, man accused of killing his brother and a family cat allegedly told police he had a "fit of madness" when they responded to the scene of the crime.

Matthew Hertgen, accused of killing his brother and family cat in a Princeton apartment on Feb. 22, appears in a New Jersey courtroom for a detention hearing.

Matthew Hertgen is facing multiple charges, including first-degree murder, for the death of his younger brother, Joseph ...