A 17-year-old Massachusetts boy who allegedly used ChatGPT to explore fantasies about killing his family is accused of murdering his mother and younger brother inside the family’s home in an affluent Boston suburb, and was ordered held without bail Thursday as prosecutors revealed new details about the violent scene.Arjun Aravind, of Acton, was arraigned Thursday in Concord District Court on two counts of murder, two counts of assault and battery with a dangerous weapon and two counts of assault and battery, the Middlesex District Attorney’s Office confirmed to Fox News Digital.He was charged as an adult under Massachusetts law and he pleaded not guilty, the DA’s office said.Middlesex District Attorney Marian Ryan said Wednesday that investigators uncovered what she characterized as “concerning behavior” by Aravind in the period before the deaths, including internet activity and the use of ChatGPT to explore theoretical or fictional scenarios involving the killing of his family.DISPATCH AUDIO RELEASED IN MICHIGAN FAMILY MURDER-SUICIDE AS TROUBLED FAMILY’S SECRETS EMERGERyan said Aravind allegedly used the artificial intelligence chatbot to “make searches including for theoretical ideas or fantasies regarding killing his family.”The teen is accused of murdering his mother, Sudha Venkatesan, 45, and his 14-year-old brother, Siddharth Aravind, who were found dead Tuesday evening inside the family’s Martha Lane home.Acton is an affluent community about 30 miles northwest of Boston and the family had recently moved to the town in part for its schools and a support system for the children, Aravind’s defense attorney, Debra DeWitt, told CBS News Boston following Thursday’s hearing.Authorities were called to the home shortly after 6:30 p.m. Tuesday after Aravind’s father requested a well-being check.The father had been at work and was worried after a tutor who arrived at the house was unable to get inside, according to authorities. After repeated attempts to contact his family went unanswered, he contacted police.GET BREAKING NEWS ALERTSMAN ACCUSED OF KILLING TWO TEENS CLAIMED HE WAS CARJACKED — HIS OWN DASHCAM FOOTAGE SHOWS OTHERWISE: COPSResponding officers entered the home and found Siddharth dead on the first floor. Venkatesan was subsequently found dead in the finished basement, authorities said.Prosecutors said Thursday that investigators encountered evidence of a violent physical struggle inside the home and that preliminary evidence indicated both victims suffered blunt-force trauma.The official causes of death remain pending determinations by the medical examiner.CLICK HERE FOR MORE U.S. NEWSVenkatesan was last seen alive at about 7 a.m. Tuesday, when her husband left for work, according to Ryan.Siddharth went to a recreational facility around 9 a.m. and returned home shortly after noon.FOLLOW US ON XInvestigators quickly discovered that Venkatesan’s green Honda Accord was also missing from the residence.TEEN SUSPECT IN MURDER OF TWO BANK EMPLOYEES IN KENTUCKY LEADS POLICE ON WILD 130 MPH CHASEAravind was located at approximately 3:40 a.m. Wednesday inside his mother’s vehicle in a parking lot in nearby Wayland, Massachusetts, and was taken into custody without incident.FOLLOW THE FOX TRUE CRIME TEAM ON XLISTEN TO THE NEW ‘CRIME & JUSTICE WITH DONNA ROTUNNO’ PODCASTProsecutors said Thursday that investigators recovered several items from the car that they believe corresponded with evidence from the scene, though officials have not publicly identified those items.SIGN UP TO GET THE LATEST TRUE CRIME NEWSCourt documents also indicate Aravind’s father had become concerned about his son’s recent behavior and internet use and had begun hiding knives inside the home, CBS News Boston reported.LIKE WHAT YOU’RE READING? CLICK HERE FOR MOREAravind received medical treatment for injuries to his hand before Thursday’s appearance and was medically cleared to attend court, prosecutors said.SEND US A TIPHis attorney requested that he receive a mental health evaluation. When the judge asked whether the request concerned Aravind’s competency to stand trial or his potential criminal responsibility, DeWitt said that had not yet been determined.GOT A TIP?Aravind is due back in court Sept. 11 for a probable cause hearing.Fox News Digital has reached out to OpenAI for comment.GET BREAKING NEWS BY EMAIL