The agency's case is based on a National Investigation Agency complaint filed against the accused and Pakistan-based organisation Falah-i-Insaniyat Foundation.
The case posed unique challenges, such as a lot of evidence having blown to pieces in the suicide attack and seven accused being subsequently killed in encounters. However, the central agency used forensic tests including DNA profiling of the meagre evidence to breach the dead ends.
The 13,500-page chargesheet names Masood Azhar, his brothers -- Abdul Rauf and Ammar Alvi -- and his nephew Mohammed Umer Farooq, who had infiltrated into India in 2018 and was subsequently killed in one of the encounters in South Kashmir.