Lal Babu, Santosh and Shivji Paswan, all hailing from Bihar, were arrested on Saturday, helped by CCTV footage provided by school authorities.
The authorities found on November 26 that three LPG gas cylinders and a complete music system of S D Public School in Pitam Pura have been stolen.
The school gave CCTv footage to police who zeroed-in on two persons Santosh and Lal Babu who were living in nearby slum cluster.
"The duo were arrested and they confessed to their involvement in the incident," a police official said adding this led to the arrest of Shivaji.
