Senator Ronald Dela Rosa briefly sought refuge in the Senate last week while asking the Philippine Supreme Court to stop an attempt by government agents to arrest him.

The fugitive senator, the former national police chief in the early years of Duterte’s anti-drug campaign, barely escaped arrest before wild scenes erupted on May 13.

Shots were fired during the mayhem that sent senators scurrying into their offices for shelter.

Philippines authorities presented their initial findings into the incident at a public briefing on Tuesday, where interior secretary Juanito Victor Remulla identified Senate Sergeant-at-Arms Mao Aplasca as the person who fired the first shot.

Aplasca’s shot outside the building prompted a government agent to fire a warning shot in return, he said.

“All evidence points that there was no attack on the Senate,” Remulla said, adding that government agents “never set foot” inside the Senate building.

Police chief Jose Nartatez said Aplasca had been called to a police inquiry to have his gun tested but he had not yet complied.

CCTV footage subpoenaed by investigators from the Senate appeared to show him firing a rifle.

Aplasca is a former classmate of Dela Rosa and said in an interview with a local television station that he had fired the first warning shot when he saw a group of armed men he thought were trying to enter the Senate.

Senate president Alan Peter Cayetano has also said security guards fired warning shots because it was feared the Senate had come under attack.

Nartatez said Dela Rosa possibly left the Senate last Wednesday in a vehicle registered to his ally, Senator Robin Padilla, to an unknown destination.

Dela Rosa is accused along with Duterte and others of the “crime against humanity of murder” for their roles in the deadly crackdown on illegal drugs.

Duterte was arrested last year and is awaiting trial by the ICC in The Hague.