A 17-year-old Indian-origin boy in Massachusetts has been charged with allegedly killing his mother and 14-year-old brother, with investigators saying he had recently used the internet and ChatGPT to search for theoretical ideas and fantasies about killing his family.

Arjun Aravind, a resident of Acton, faces two counts of murder along with assault and battery charges and motor vehicle-related charges following the deaths of his mother, Sudha Venkatesan, 45, and younger brother, Siddharth Aravind, 14.

According to the Middlesex County District Attorney's Office, Arjun had recently displayed concerning behaviour, including searches on the internet and ChatGPT involving "theoretical ideas or fantasies regarding killing his family."

The investigation into the motive and circumstances surrounding the deaths is continuing.

The deaths took place Tuesday at the family's home on Martha Lane in Acton, around 48 km from Boston.

Acton Police received a call shortly after 6.37 pm on August 11 from Arjun's father, who had been unable to contact his family. A tutor who was expected to visit the house had also been unable to reach anyone inside.

Arjun's father had last spoken to his wife, Sudha, early that morning before leaving for work. Siddharth was last seen around noon.

When police arrived at the house, they found both victims dead. Siddharth was found on the first floor, while Sudha was found in the finished basement.

Both victims had "obvious trauma", officials said. The Chief Medical Examiner has not yet released the exact cause and manner of death. Investigators are also still determining what weapon, if any, was used in the killings.

Teen allegedly fled in mother's car

Police said Arjun was not at the house when officers arrived and had allegedly fled in his mother's car.

Investigators initially failed to locate him and issued alerts to law enforcement agencies and the public.

Early Wednesday morning, police in Wayland, Massachusetts, responding to an unrelated alarm at a parking lot, found the vehicle with Arjun inside. He was taken into custody without incident.

Arjun was expected to be arraigned in Lowell Juvenile Court on Wednesday. Because the Juvenile Court does not have jurisdiction over a murder charge, he is expected to face the murder and related assault charges in Concord District Court.

The investigation remains ongoing.

With PTI inputs