New Jersey authorities have arrested a Princeton man accused of killing his former college athlete brother and a cat, allegedly with a knife and golf club, according to the Mercer County Prosecutor's Office. Matthew Hertgen, 31, is charged with first-degree murder in connection with the death of Joseph Hertgen, 26, as well as third- and fourth-degree weapons charges related to possession of a golf club and knife. He is also facing an animal cruelty charge. Princeton police initially responded to a 911 call on Feb. 22 around 11:16 p.m. reporting a fire and a dead body at the Michelle Mews Apartments complex. "When officers responded to the scene, they found Matthew Hertgen, who was determined to be the 9-1-1 caller, in the residence along with the body of the victim, which exhibited signs of blunt force trauma and lacerations," the Mercer County Prosecutor's Office said in a press release. WEALTHY NEW JERSEY TOWN PET STORE OWNER SHOT WITH CROSSBOW AFTER EXOTIC BIRD ROBBERY Joseph Hertgen was pronounced dead at the scene, and his autopsy results are pending. Local and state officials are investigating the 26-year-old's death as a homicide. SAFARI OPERATOR SUED AFTER NEW JERSEY WOMAN MAULED TO DEATH BY A HIPPO Both brothers played college soccer — Matthew at Wesleyan University in Connecticut and Joseph at the University of Michigan. NJ LAWSUIT CLAIMING OIL COMPANIES CAUSE CLIMATE CHANGE DEALT MASSIVE BLOW IN COURT CLICK HERE TO GET THE FOX NEWS APP The investigation into Joseph's death is ongoing. Mercer County authorities are asking anyone with information about the alleged crime to contact the Homicide Task Force Sgt. Will Jett at 609-331-5010 or Det. Karl Johnson at 609-439-5258.