Local SWAT snipers saw Trump rally gunman nearly 2 hours before assassination attempt, text messages show

A local SWAT sniper noticed the suspected gunman at former President Donald Trump's deadly campaign rally earlier than previously known, according to text messages obtained by ABC News.

On July 13, in what authorities have said was an assassination attempt, Thomas Matthew Crooks, 20, opened fire at the event in Butler, Pennsylvania, killing one spectator, critically injuring two others and leaving Trump bleeding from his right ear.

At 4:26 p.m. -- nearly two hours before the shooting began -- a sniper leaving the area where local SWAT members assembled saw Crooks "sitting to the direct right on a picnic table about 50 yards from the exit," the text message said.

Watch: ABC News' exclusive first interview with the local SWAT team on the ground during Trump's assassination attempt airs in its entirety on "Good Morning America" on Monday, July 29, at 7 a.m. ET.

The obtained text messages were shared among snipers in the American Glass Research (AGR) building area, which was being used as a staging area for local police, who were inside the structure.

The sniper who alerted others that Crooks was lurking in the area noted Crooks was likely aware of the snipers' position, writing, "because you see me go out with my rifle and put it in my car, so he knows you guys are up there."

Less than an hour later, as ABC News previously reported, a member of that same sniper team identified Crooks as suspicious -- and shortly after that, called it into local command, warning of the suspicious presence.

In their first public comments since the assassination attempt, the Beaver County SWAT team on the ground that day and their supervisors spoke exclusively with ABC News Senior Investigative Correspondent Aaron Katersky.

It is the first time any key law enforcement personnel on-site on July 13 have offered first-hand accounts of what occurred.

"We were supposed to get a face-to-face briefing with the Secret Service members whenever they arrived, and that never happened," said Jason Woods, lead sharpshooter on the SWAT team in Beaver County, Pennsylvania.

"So I think that was probably a pivotal point, where I started thinking things were wrong because it never happened," Woods said. "We had no communication."

The Secret Service, whose on-site team was supplemented as usual by local, county and state law-enforcement agencies, was ultimately responsible for security at the event. The Washington Post reported over the weekend that Secret Service agents have complained they were not made aware of the warnings.

Secret Service spokesman Anthony Guglielmi declined to respond directly to the comments from Woods and his colleagues. He said the agency "is committed to better understanding what happened before, during, and after the assassination attempt of former President Trump to ensure that never happens again. That includes complete cooperation with Congress, the FBI and other relevant investigations."

Beaver County Chief Detective Patrick Young, who runs the Emergency Services Unit and SWAT team, said collaboration is key when lives are on the line.

"I believe our team did everything humanly possible that day," Young said. "We talk a lot on SWAT that we as individuals mean nothing until we come together as a team."