The man who tried to assassinate Donald Trump was aided by a series of baffling failures on the part of Secret Service.

Among the issues being looked at is the agency's failure to act on warnings from local police of a suspicious person.

The reports somehow never made it to the Secret Service detail assigned to protect Trump, the Washington Post reported.  

As a result, Trump's detail didn't realize something was wrong until the shooting started at 6:11 p.m.

Secret Service detail blindsided?

Roughly 25 minutes before the shooting, a local police sniper noticed gunman Thomas Matthew Crooks acting suspiciously and snapped a picture.

Col. Christopher L. Paris, head of Pennsylvania State Police told Congress last week that a state trooper verbally relayed the warning to agents at the Secret Service command center. But those reports never reached Trump's security detail, sources told the Post. 

When the gunshots rang out at 6:11 p.m., some of Trump's advisers thought it was fireworks. Trump's advisers do not understand why they received no warning, as they would have delayed the event if they knew something was wrong, the Post reported.

The Secret Service's director, Kimberly Cheatle, resigned last week after mounting pressure to step aside. She had told Congress that suspicious people don't always turn out to be threats.

A source echoed Cheatle's sentiment to the Post but added that suspicious reports usually come from inside the secure area. Crooks was outside the security checkpoints when he was spotted using a rangefinder, which should have raised a more urgent alert.

Briefing "never happened"

Crooks was able to take a clear shot at Trump from a rooftop less than 200 yards away. Trump turned his head just in time and the bullet grazed his ear.

Local snipers who were stationed in an adjoining building noticed Crooks roughly 90 minutes before the shooting. A police sniper ending his shift saw him sitting at a picnic table outside of the warehouse and alerted his team, the New York Times reported.

Around 5:38 p.m., a different sniper saw Crooks and snapped a picture.

"I did see him with a range finder looking towards stage. FYI. If you wanna notify SS snipers to look out," he wrote.

The local police team told ABC News that they had no contact with Secret Service before the shooting. A briefing that was supposed to take place "never happened."

"We had no communication," said Jason Woods, team leader for Beaver County's Emergency Services Unit and SWAT sniper section. "Not until after the shooting."