A masked man in a car broke through the VIP gate at Delhi's legislative assembly complex, leaving a bouquet and sparking a major security breach.
The suspect, identified as Sarabjit Singh, was later detained and two others were arrested after a two-hour manhunt.
Singh's family claimed he was not well and had periods of uncontrollable behaviour, which may have led to the incident.
Police are investigating the breach, with bomb squad teams and crime branch called in, but nothing suspicious has been found yet.
The car, a white Tata Sierra SUV, was registered in Singh's name and had an Uttar Pradesh registration number.
