The Class 11 student, who is accused of murdering a Class 2 boy in Gurugram’s Ryan International School, was the Central Bureau of Investigation’s main suspect for over a month, NDTV reported on Friday.

According to a Haryana court order, the agency had raided the teenager’s house on September 29 and seized a few articles and documents. The CBI’s action came about a week after it took over the case from the local police, who had arrested a bus conductor, The Indian Express reported.

The agency said it has forensic evidence, CCTV footage and witnesses statements, apart from the teenager’s confession statement, to back their charge, India Today reported. The 16-year-old reportedly killed the Class 2 boy as he wanted a parent-teacher meeting and an examination to be postponed.

The Class 2 boy was found murdered with his throat slit inside one of the washrooms of the school on September 8.