The Princeton soccer player accused of brutally murdering his little brother and setting the family cat on fire is believed to have ripped out his sibling's eyeball before eating it, according to police. Matthew Hertgen, 31, was charged with first-degree murder, various weapons offenses and animal cruelty for killing his 26-year-old brother Joseph Hertgen in their luxurious New Jersey apartment Saturday night. A bloody knife, plate and fork were discovered near Joseph at the scene, leading authorities to believe Matthew ate the organ, a law enforcement source told the New York Post. Princeton Police responded to a 911 call reporting that there was a fire and a dead body within one of the residences inside the Michelle Mews Apartments, according to the Mercer County Prosecutor’s Office. When officers responded to the scene, they found Matthew, who had called 911, in the residence along with the beaten and cut up body of the victim and a dead cat. DailyMail.com learned that Matthew - who attended the ritzy private college Wesleyan University - had schizophrenia and was in and out of mental hospitals prior to his brother's murder. Police believe Matthew used a knife and a golf club to brutally assault and murder his brother, who worked as a banker after graduating from the University of Michigan. On Wednesday, two men from Servpro Cleaning Company made three trips from apartment 621 carrying different contents from inside. As they loaded the items into the truck a DailyMail.com reporter approached to inquire if they were cleaning apartment 621. They did not respond, but when asked to nod if it was the right apartment, a man did so before driving off. The two man crew was there for about four hours on Wednesday and spent several hours there on Tuesday as well. A woman who lives in the building said that building management sent a letter out on Monday morning regarding the tragedy but little was shared. ‘They didn’t give any details or give any people’s names and then shortly after you see all the articles that came out. It is terrible,’ said the woman, who did not want to be identified. She said that she never saw any of the family members but said that the apartment would be too small to have four people living in that unit. Another woman, who has been living in Princeton for more than 40 years said she heard about the crime and called it ‘unbelievable.’ Recalling the age of the older brother, who is 31, the woman added: ‘t’s a typical age for mental illness to emerge between 23 and 33. It’s just textbook for men and women.’ One couple, who lives nearby Michelle Mews said they were ’shocked’ about the gruesome crime. ‘It wasn’t very Princeton-ey,’ said the husband. The wife chimed in, ‘Oh Lord. That brother had some much rage. I want to know what the motive was.’ A young couple who just moved into the high-end residence were absolutely spooked by the murder. She said, ‘Living here in the safeness of Princeton which is right out of Gilmore Girls and then suddenly there is a brutal murder and then he killed the cat. He had so much rage.’ Another man was in disbelief after hearing of the murder in the college town. 'Their American boys from an affluent family. It's sad,' he told DailyMail.com. A realtor for the area told DailyMail.com that the apartment the brothers were living in was a rental. The monthly rate is between $6,000-7,000 a month. He said he believes the apartment was in the mother’s name and they have had it for a while. A man who did not identify himself but appeared to be with the building, possibly security, said ‘We are just asking that you leave everybody alone. Let them mourn. We don’t want aggravation over here.’ The Hertgen brothers were raised in the quaint coastal town of Toms River by their multi-millionaire tech mogul father David and mom Debra. Their father, David Hertgen, is the president and CFO of business internet provider WiLine Networks, according to his LinkedIn. They also have a third brother, David Jr., who works for their father's company. He lives in a Greenwich Village apartment in New York City. DailyMail.com went to the corporate headquarters of WiLine Networks on Tuesday night but the offices were closed. Someone in the building said that there is usually one to two people at the office until 9pm but the offices closed early. When contacted by DailyMail.com, the brothers' father David and older sibling David Jr. did not respond. The affluent brothers grew up in a four-bed, three-bath mansion in Toms River, New Jersey, which was kitted out with a swimming pool in the backyard. Online records show the home, which is worth an estimated $1.2 million, was sold in 2018. According to records the parents were living in the unit since 2018 which coincides with the selling of their mansion that same year. David is a registered Democrat, but in 2023, he donated $1,000 to West Virginia Republican senate candidate Alex Mooney, records show. The Toms River school district the sibling previously attended told DailyMail.com: 'The news and circumstances surrounding the death of Joseph Hertgen is unspeakably sad and tragic. 'We mourn the passing of one of our own—a beloved former student athlete and friend to many—and express our deepest condolences and sympathies to everyone who knew and loved Joseph.' After the shock murder, disturbing social media posts shared by Matthew came to light. One day before the brutal murder, heavily bearded Matthew posted a chilling selfie on Facebook of himself - laying expressionless on the floor next to a cat toy that costs $7.99 from PetSmart. The toy was presumably owned by the Hertgen family's pet cat, that was also slaughtered during the homicide at the home near Princeton. Wearing a black t-shirt, the beady-eyed selfie showed the alleged murderer lying on a beige carpet floor. It was uploaded to the social media site without a caption. Matthew's grown-out facial hair and deadpan stare matched his mugshot - which was released by prosecutors late on Monday. He was wearing a white t-shirt with a black jacket. His most recent written post was from September 4, in which he shared a disturbing poem about death and fire. The content was graphic - and seemed to be an original poem written by Matthew himself. 'Someone sits alone in that room. That room where the walls shake. He still has a pulse. Blood still flows through his veins. But something is wrapped around him. Squeezing him. Choking him. Suffocating him. Tightly wound around his head. Fastened deep in his throat. Blood oozes out of his eyes,' Matthew said. 'His body is surrounded by fires. The fires are blazing inside of him. He is combusting into nothing. His eyes redden by the minute. Creases form on his forehead. He keeps his mouth tightly closed.' Meanwhile, his little brother's social media images gave a glimpse into his as he was seen posing in front of the Eiffel tower with friends in 2017 and enjoying ice cream on a bridge in another. Joseph was seen in another image surrounded by his University of Michigan soccer teammates. Matthew was previously arrested in February 2017 in South Jersey for drunk driving, the New York Post reported. He lost his license for three months because of it. The cause and manner of Joseph's death are pending the results of an autopsy - and the motivation for his killing is unknown.