• Former President Donald Trump survived an assassination attempt at a Pennsylvania rally.
• A former Secret Service agent says counter-snipers would usually have "360-degree coverage" for similar events.
• Investigators will likely look into the event's "site plan."

A former Secret Service agent said counter-snipers at the Pennsylvania rally where a would-be assassin wounded former President Donald Trump should have had "360-degree coverage" of the event and surrounding buildings.

"I don't know how many they had, but they usually always look for 360-degree coverage," former Secret Service agent Anthony Cangelosi told Business Insider. "So that's one thing that's going to be considered."

The Federal Bureau of Investigation identified the shooter as a 20-year-old man from Bethel Park, Pennsylvania.

Cangelosi, who is now an adjunct professor at the John Jay School of Criminal Justice at the City University of New York, said the primary question law enforcement would likely be asking is how the suspect could have made it to the top of a nearby building undetected.

Butler Township Sheriff Michael Slupe told The Washington Post that a local officer encountered the suspect before the shooting but dropped to the ground because he did not have his weapon.

For a large event where the president or former president is speaking, the Secret Service on the scene would typically work with law enforcement to design a "site plan" with a mock-up of the event space and all surrounding buildings, Cangelosi said.

This plan will be paramount for investigators in determining what possible failures occurred during the rally, according to Cangelosi.

"All the posts — meaning personnel, Secret Service or uniformed police officers, where they were positioned, what their duties were to secure that post, what considerations were given to the outer perimeter, in this case, the other building," will be included in the site plan, Cangelosi said.

Cangelosi said the Secret Service would sometimes use "counter-sniper response units," which are posted on the ground and can quickly move into position if they notice a threat.

"However, time could also be of the essence, right?" Cangelosi said. "You might not have the ability to send a counter-sniper response team up to the location"

Snipers often quickly have to make a decision when they notice a potential threat like an open window or a person sitting on a roof Cangelosi said.

"What if you find out, 'Oh, I just killed a kid, 20-year-old kid who loves the protected, and he couldn't get in the venue, and he just wanted to get up on that roof,'" Cangelosi added. "No one wants to be in that position."

Cangelosi said he expects the Secret Service to amp up security at future events moving forward. Trump has already confirmed he plans to speak at the Republican National Convention in Wisconsin next week.

"The Secret Service is well aware of the fact that they have to be perfect all of the time," Cangelosi said. "And the one time you're not, it's going to bring an increased scrutiny."

• Thomas Matthew Crooks shot at Donald Trump on Saturday during a rally in Pennsylvania.
• A local officer encountered Crooks on the roof before the shooting but retreated, WaPo reported. 
• Law enforcement and the US Secret Service are facing scrutiny following the incident.

A municipal police officer at Donald Trump's rally in Pennsylvania encountered the shooter before the assassination attempt but retreated, according to The Washington Post.

Butler County Sheriff Michael T. Slupe told the outlet that the officer inspected the roof after an unnamed law enforcement agency requested identification of a "suspicious individual" at the rally, the Post reported.

After the officer pulled himself up high enough to see onto the roof of a building near the rally, the shooter, now identified as Thomas Matthew Crooks, turned around and aimed his gun at the officer, prompting him to drop back to the ground, the outlet said.

Slupe said the officer did not have a gun in his hand at the time because he was holding onto the roof's ledge.

"He lets go because he doesn't want to get killed," Slupe told the outlet.

Crooks then shot at Trump. Secret Service agents quickly surrounded the president, who later confirmed in a Truth Social post that a bullet struck his ear.

A Secret Service sniper fatally shot Crooks.

The Butler County Sheriff's Office did not respond to a request for comment from Business Insider.

Law enforcement officials and the Secret Service are facing criticism following the incident.

A former intelligence officer at the Defense Intelligence Agency told BI said it's "mind-boggling" that Crooks managed to reach the rooftop and have a clear shot at Trump.

An AP analysis of the footage found that Crooks managed to get "astonishingly close" to the stage. According to the outlet, the roof was less than 164 yards from where Trump stood onstage.

President Joe Biden ordered an independent probe of Trump's rally security on Sunday in the shooting's aftermath.

"I've directed an independent review of the national security of yesterday's rally, and we will share the results of that independent review as well," Biden said.

GOP House Speaker Mike Johnson said the House would investigate events at the rally. On Saturday, the Federal Bureau of Investigation announced it assumed the lead role in the investigation in a post on X.

Trump will speak at the Republican National Convention in Milwaukee this week.

"In this moment, it is more important than ever that we stand United, and show our True Character as Americans, remaining Strong and Determined, and not allowing Evil to Win," he said in a Truth Social post.

• The threat of political violence has been an unfortunate element of many open societies.
• In a YouGov poll taken after the Trump rally shooting, half of US adults said it's "a very big problem."
• President Joe Biden is seeking to project an image of unity and calm a stunned nation.

One thing is clear after shots were fired at former President Donald Trump during his Saturday rally in Pennsylvania: Americans are freaked out.

In a YouGov poll taken after the shooting, 50% of adults said that political violence is "a very big problem" in the US. An additional 32% of adults said that political violence is "somewhat of a problem" in American society.

Only 2% of American adults in the new survey felt that political violence isn't an issue in the country.

There's a major disparity among age groups when it comes to the issue. While 37% of Americans aged 18 to 29 rated political violence as "a very big problem," a whopping 63% of Americans aged 65 years old and older agreed with that statement.

One explanation for the gap could be the memories of societal turbulence from the 1960s.

For Americans who lived through the 1960s or are tied to that era in some way, the assassinations of major figures like President John F. Kennedy, the Rev. Dr. Martin Luther King Jr., and New York Sen. Robert F. Kennedy collectively represented some of the darkest days of that decade.

A stunning 67% of the respondents said the current political climate makes political violence "more likely" than normal.

Chaos erupted on Saturday evening in Butler, Pennsylvania, where Trump was fired upon while holding a political rally ahead of the Republican National Convention.

Secret Service officers returned fire, killing a 20-year-old shooter later identified as Thomas Matthew Crooks.

Trump said he was shot in his right ear but was otherwise stable. One attendee was killed and two others were critically injured. The FBI on Sunday announced that it is probing the assassination attempt as a potential act of domestic terrorism.

The rally-goer who was killed has been identified as Corey Comperatore, a 50-year-old firefighter.

The failed assassination attempt stunned the nation and brought the tense presidential race to a near-standstill.

President Joe Biden's reelection campaign pulled television ads and paused "outbound communications" following the shooting.

Biden emphasized a message of unity as he spoke about the incident at the White House on Sunday.

"Unity is the most elusive goal of all, but nothing is more important than that right now — unity," he said. "We'll debate and we'll disagree. But we're not going to lose sight of who we are as Americans."

The president is set to address the nation from the Oval Office on Sunday.

Trump is still planning to speak at the Republican National Convention in Milwaukee this week, where he's set to formally accept his party's presidential nomination.

YouGov surveyed 4,339 American adults in its poll, which was conducted on July 14.

• The shooting suspect who attempted to assassinate Donald Trump at a Pennsylvania rally used an "AR-style" rifle, the FBI says.
• Police identified the shooter as a 20-year-old male from Bethel Park, Pennsylvania.
• The FBI confirmed the weapon Crooks used was purchased legally.

The would-be assassin of former President Donald Trump at a Pennsylvania rally on Saturday used an "AR-style" rifle that was purchased legally, the FBI believes.

The FBI, on early Sunday morning, confirmed the shooter as Thomas Matthew Crooks, 20, of Bethel Park, Pennsylvania.

FBI Special Agent Kevin Rojek, director of the agency's Pittsburgh field office, said in a news conference Sunday afternoon that the FBI recovered an "AR-style 556 rifle which was purchased legally."

"We located the weapon at the scene, located immediately adjacent to the shooter," Rojek said.

The FBI said it believes Crooks's father legally purchased the weapon used in the shooting.

The FBI's primary focus is determining Crooks's motive and movement leading up to the shooting.

Rojek told reporters that authorities have no indication that Crooks suffered from mental health issues.

"At present, we have not identified an ideology associated with the subject, but I want to remind everyone that we're still very early in this investigation," Rojek told reporters. "We are working hard to determine the sequence of events related to the subject and his movements in the hours, days, and weeks prior to the shooting."

• Former President Donald Trump was wounded at a rally Saturday in what is being investigated as an assassination attempt.
• Trump was seen with blood on his face as he clutched his ear in front of the screaming crowd.
• Trump was whisked to safety by the Secret Service. President Joe Biden later spoke with the ex-president.

Former President Donald Trump was wounded during a Saturday campaign rally in Pennsylvania, in an incident that is being investigated as an attempted assassination.

Trump was speaking to supporters at the Butler, Pennsylvania, rally when gunshots rang out at his rally, and he was subsequently seen with blood on his face. He was then seen defiantly raising his fist before being whisked off stage by Secret Service agents.

The Secret Service said in a statement that a suspected shooter opened fire toward the stage from an "elevated position" outside the venue where Trump was holding his rally.

A representative for the FBI confirmed to Business Insider early on Sunday that the shooting suspect is Thomas Matthew Crooks, 20, of Bethel Park, Pennsylvania.

Kevin Rojek, a spokesperson for the FBI, in a press briefing shortly after midnight on Sunday morning, said the agency had deemed the incident an attempted assassination of the former president.

A bystander at the rally died in the shooting, the Secret Service said, while two others were critically injured. The Secret Service said its agents killed the gunman.

The victim killed at the rally was identified as Corey Comperatore, a 50-year-old former fire chief of the Buffalo Township Volunteer Fire Company in Pennsylvania.

In a Truth Social message posted several hours after the shooting, Trump thanked the Secret Service "and all of Law Enforcement, for their rapid response on the shooting that just took place in Butler, Pennsylvania."

"Most importantly, I want to extend my condolences to the family of the person at the Rally who was killed, and also to the family of another person that was badly injured. It is incredible that such an act can take place in our Country. Nothing is known at this time about the shooter, who is now dead."

Trump wrote that he was shot with "a bullet that pierced the upper part of my right ear."

"I knew immediately that something was wrong in that I heard a whizzing sound, shots, and immediately felt the bullet ripping through the skin," Trump wrote. "Much bleeding took place, so I realized then what was happening. GOD BLESS AMERICA!"

A Trump spokesperson called the shooting a "heinous act" but said the former president and presumptive GOP nominee was "fine."

NBC News correspondent Darren Botelho reported security at the event could be heard saying, "The shooter is down," following the incident.

David McCormick, the Republican nominee for Senate in Pennsylvania, had been seated in the front row of the rally and told Politico it appeared a member of the crowd behind him had been shot.

"All the sudden shots started to crack, someone behind me appears to have been shot," McCormick told Politico. "There's lots of blood, and then the Secret Service were all over President Trump."

Politicians from across the ideological spectrum were quick to condemn political violence and wish Trump a speedy recovery.

In a statement issued following the shooting, President Joe Biden said he was "grateful to hear" that Trump is safe and doing well.

"I'm praying for him and his family and for all those who were at the rally as we await further information," Biden's statement continued. "Jill and I are grateful to the Secret Service for getting him to safety. There's no place for this kind of violence in America. We must unite as one nation to condemn it."

Biden later addressed the nation, saying the shooting was "sick" and calling on Americans to stop political violence.

"It's one of the reasons we have to unite this country," Biden said. "We cannot allow for this to be happening. We cannot be like this. We cannot condone this."

The Biden campaign later said it was pulling down TV ads in the wake of the shooting. The president spoke directly with Trump on Saturday, later adding that he had a "short but good conversation" with the former president.

Biden is set to address the nation from the Oval Office on Sunday evening.

House Speaker Mike Johnson of Louisiana vowed in a post on X that the House would probe the "tragic events" that occurred at the rally.

"The American people deserve to know the truth," Johnson wrote. "We will have Secret Service Director Kimberly Cheatle and other appropriate officials from DHS and the FBI appear for a hearing before our committees ASAP."

Johnson also weighed in on the shooting during a Sunday appearance on NBC's "Today," denouncing political violence and urging leaders to help "turn the rhetoric down" in the US.

"We need leaders of all parties, on both sides, to call that out and make sure that happens so that we can go forward and maintain our free society that we all are blessed to have," he said.

With the Republican National Convention in Milwaukee set to begin this week, the GOP over the past few days had been largely focused on the event as a showcase for their party. Trump so far has not changed his plans regarding his appearances at the convention.

But the shooting incident threatens to upend an already tumultuous presidential contest with the general election now less than four months away.