New Delhi: The 16-year-old student accused of murdering Pradyuman Thakur, a Class II student of Ryan International School in Gurgaon, will be tried as an adult, the Juvenile Justice Board ruled on Wednesday.

The board passed the order in response to a plea by the CBI and Pradyuman's father that the accused teenager should not be treated as a juvenile.

"The board, while delivering the verdict, said the crime allegedly committed by him was heinous. It held that the circumstances showed the accused was mature enough to understand the consequences of his act. Under the amended Juvenile Justice (Care and Protection of Children) Act, 2015, the accused teenager will be tried for murder under the Indian Penal Code," a CBI officer told The Telegraph.

According to the amended Act, juveniles between the ages of 16 and 18 years accused of heinous crimes can be tried under the IPC based on the juvenile court's assessment.

Heinous crimes, such as rape, murder, robbery and acid attacks, have been categorised as those that carry jail terms of seven years or more under the IPC.

Had the board treated the accused teenager as a juvenile, even if found guilty, he would have been sent to a reformatory home and released when he turned 18.

The board transferred the case to the sessions court in Gurgaon. Since the accused is a minor, he cannot be identified under the existing law.

The victim's counsel, Sushil Tekriwal, termed the order "historic".

Sources said the board arrived at the decision after examining the sociological and psychological reports of the accused, which had details of his family and friends and his lifestyle.

A committee of psychologists set up by the board had prepared a report after talking to his schoolmates, parents, friends, neighbours and relatives.

The committee also examined the physical and mental ability of the accused to commit such an offence, his capability to understand the consequences of the crime and the circumstances under which he did so.

The CBI arrested the Class XI student on November 8, saying he slit Pradyuman's throat with a knife in a school toilet in early September to get exams and a parent-teacher meeting postponed.

The agency had said Haryana police, which initially probed the case, had implicated bus conductor Ashok Kumar at the behest of "some people, including local politicians".

Last month, Ashok was granted bail after the CBI did not oppose his plea. The police had claimed Kumar had killed Pradyuman after he resisted his attempts to sexually assault him.

Pradyuman's father Barun Thakur welcomed the board's ruling. "We are hopeful that justice will be done to my son. Although it's a long way to go, the first hurdle is over," Barun said.

The accused's family expressed shock and disappointment. The accused's father told reporters: "We are shocked and shattered."

The accused's counsel, Sandeep Aneha, who had argued that the main purpose of the Juvenile Justice (Care and Protection of Children) Act, 2015, was to ensure juveniles' welfare, said the family would challenge the board's ruling.