Police snipers were in the building when the gunman fired from the roof at a Trump rally

The revelations add to a growing list of questions about the Secret Service’s plan to secure the areas outside the perimeter and the failure of law enforcement to respond quickly enough to several early warnings of suspicious activity. The Washington Post reported in a video analysis on Monday that bystanders at the Trump rally in Butler, Pennsylvania, warned local police that they had seen a man climbing onto the roof of the building. A video posted on social media shows a man shouting “Officer! Officer!” as others point to the building. “He’s on the roof!” one woman says.

The Secret Service employee’s account also highlights the emerging tensions between that agency and local authorities over who was responsible for ensuring the shooter had a clear view of what was happening. The Secret Service was responsible for the overall security plan, but the agency has said it relied on local law enforcement for areas outside the security perimeter. The Agr building was not within the perimeter, so visitors had to pass through a metal detector before entering the building.

The Secret Service official said the sniper team in the building was from Beaver County, which borders Butler County, where Saturday’s rally took place. Local authorities said it is common for SWAT teams in surrounding counties to bolster security at large events across western Pennsylvania.

The Beaver County District Attorney’s Office confirmed that a county SWAT team was present at Saturday’s rally but declined to release further information, citing ongoing investigations by state and federal authorities. In a written statement Tuesday, the district attorney’s office said, “We are proud of the heroic actions of our officers.”

Butler County District Attorney Richard Goldinger said in an interview that the SWAT teams from his jurisdiction were all within the security perimeter. “The Secret Service was in command and so it was their responsibility to make sure the venue and the surrounding area were safe,” he told the Post. “That’s common sense, in my opinion. That’s their job.”

He added: “When they blame local law enforcement, I think they are shifting the blame away from themselves when the blame lies in their own hands.”

Local news station BeaverCountian reported Monday that snipers were in the building behind the event’s security perimeter. The station reported that a Beaver County police officer alerted a command center that he saw a man with a rangefinder – a device that helps estimate distances – before shots were fired.

The Secret Service sniper who killed the gunman, 20-year-old Matthew Crooks, had him in his sights, trying to determine if he was carrying a weapon and posed a threat, the official said. Secret Service radio traffic had indicated that local police had spotted or were trying to find a suspicious man near the building. The Secret Service sniper was an experienced marksman who is considered a legend in the Secret Service for his long-range, accurate shooting.

The sniper who killed Crooks fired as soon as he saw Crooks raise a gun, the official said. That sniper killed Crooks with one shot, but seconds after he shot Trump, the official said.

The Secret Service’s security plan to avoid one of the event’s main risks — that someone outside the rally grounds could fire from high ground — called for two teams of Secret Service snipers to be stationed in front of the crowd on the roofs of two barns behind Trump’s stage. Local snipers in the Agr building would provide “cover” and monitor the crowd from behind and outside the grounds.

Secret Service Director Kimberly Cheatle said in a television interview Tuesday morning that there was a risk that a police officer would have to stand on the roof of the Agr building because the roof is slanted. “This building in particular has a slanted roof at its highest point and so there is a safety factor that has to be considered and we would not put anyone on a slanted roof,” she said. “That’s why the decision was made to secure the building from the inside.”

An analysis of the Post’s imagery of the incident revealed that the roofs of the barns where the sniper teams were located have a steeper slope than the roof of the Agr building.

The risk of a clear line of sight for a gunman is a security risk that the Secret Service has tried to take into account when planning presidential public appearances since John F. Kennedy was assassinated in 1963 by a gunman stationed in a tall building in Dallas. Current and former Secret Service agents have expressed dismay that a gunman could get so close to the former president. The incident is considered the Secret Service’s most serious security failure since the attempted assassination of President Ronald Reagan in 1981.

The Post’s video analysis shows a police officer in a black uniform looking up toward the roof of the building. The crooks began shooting two minutes and two seconds after the starting point of the newly released video, which begins with a man’s voice saying people are pointing toward the roof. The shooting began 86 seconds after the first audible attempts to alert police, according to the analysis, which dubbed several clips based on the sound of Trump’s voice over the public address system as he addressed supporters at an agricultural showground in Butler County.

The Post reported Sunday that the Secret Service is relying on local police in Beaver and Butler counties to bolster its specialized tactical teams.

Evan Hill, Aron Shaffer and Maria SacchettI contributed to this report.