Capitol Police officers were told not to use their most aggressive tactics against rioters during the Jan. 6 Capitol insurrection, a report by the agency’s internal investigator has found. According to The New York Times, Inspector General Michael A. Bolton found that Capitol Police leaders knew Trump supporters were planning to attack “Congress itself” three days before the siege.

“Unlike previous post-election protests, the targets of the pro-Trump supporters are not necessarily the counter-protesters as they were previously, but rather Congress itself is the target on the 6th,” the police department’s threat assessment read, according to the report.

“Stop the Steal’s propensity to attract white supremacists, militia members and others who actively promote violence may lead to a significantly dangerous situation for law enforcement and the general public alike,” it added.

Despite knowledge of the threat, Bolton said department leaders did not prepare for the attack in terms of training or equipment and instead told their Civil Disturbance Unit not to use their most aggressive tactics.

“Heavier, less-lethal weapons,” such as stun grenades, “were not used that day because of orders from leadership,” Bolton’s report reads. Police who were on-duty on Jan. 6 told the inspector general that those tools could have helped to “push back the rioters.”

Furthermore, officers’ riot shields were improperly stored in a trailer that was not climate-controlled and therefore “shattered upon impact” when used. Other shields were completely inaccessible, as they had been locked on a bus prior to the attack.

“When the crowd became unruly, the [Civil Disturbance Unit] platoon attempted to access the bus to distribute the shields but were unable because the door was locked,” the report read. The officers were “consequently required to respond to the crowd without the protection of their riot shields,” it adds.

According to the report, almost 140 police officers were injured during the attack and officer Brian Sicknick died later that day after being assaulted by the rioters.

The inspector general’s findings will be discussed during a Capitol Hill hearing on Thursday (April 15).