Ahead of former President Trump’s rally on Saturday, local police informed the Secret Service they couldn’t provide manpower to secure a building, from which a gunman later fired shots, The Washington Post reported.

Butler County District Attorney Richard Goldinger confirmed the Secret Service was aware of this shortfall.

Despite considering posting an officer to prevent such an incident, the gunman, Thomas Matthew Crooks, climbed the building outside the rally’s security perimeter and fired, grazing Trump’s ear, killing one attendee, and injuring two others before being killed by Secret Service agents.

Investigations are underway to determine how Crooks accessed the building and why security was insufficient, The Hill has reported.

Secret Service Director Kimberly Cheatle mentioned safety concerns about the building’s sloped roof as a reason for not posting an agent there.

Written by B.C. Begley