Sen. Ron Johnson, R-Wisc, released his official 13-page preliminary findings of his office's investigation into the assassination attempt of former President Trump.

Trump survived the assassination attempt on July 13 at a campaign rally in Butler, Pennsylvania, where alleged gunman Thomas Mathew Crooks, 20, opened fire, killing one spectator and injuring several others, including Trump, who suffered injuries to his ear.

Shortly following the incident, Johnson's office began contacting federal, state and local government entities, as well as private companies, to solicit information about the security failures at the rally, the senator's office said. The preliminary findings are based on the initial information Johnson's office obtained after the shooting.

The senator's office said he is sharing this information with the public to be transparent.

TRUMP SHOOTING: TIMELINE OF ASSASSINATION ATTEMPT RAISES QUESTIONS ABOUT HOW GUNMAN EVADED SECURITY

Republican presidential candidate former President Donald Trump is rushed offstage

Republican presidential candidate former President Donald Trump is rushed offstage during a rally on July 13, 2024, in Butler, Pennsylvania. (Anna Moneymaker/Getty Images)

The preliminary findings determined that the Secret Service did not attend a security briefing given to local SWAT and sniper teams on the morning of July 13, that local law enforcement said communications were siloed and they were not in frequent radio contact directly with the Secret Service, that local law enforcement notified command about Crooks before the shooting and received confirmation that the Secret Service was aware of the notification and that the Secret Service was seen on the roof of the American Glass Research (AGR) building with local law enforcement following the shooting.

The investigation also found that photos of the shooter were sent to the ATF for facial recognition and that local law enforcement said the Secret Service was initially not planning on sending snipers to the rally.

Johnson's office also provided a timeline of the events on July 13:

9 a.m. — Butler County Emergency Services held a briefing for the local SWAT and Sniper units from Butler County, Beaver County, and Washington County providing security for Trump's rally. The briefing outlined the security perimeter for the event and areas of responsibility for each local unit as well as staging locations, including sniper locations, for each local unit and the Secret Service.

Attendees of the briefing said no Secret Service or other federal law enforcement were present for the briefing and that the Secret Service initially did not plan to provide sniper units before changing plans for unclear reasons. It is unknown why the Secret Service did not attend the briefing.

9:27 a.m. — Crooks enters a Home Depot in Bethel Park, Pennsylvania. Video footage of the store reportedly shows him entering alone.

9:41 a.m. — Crooks purchases a 5.5 FT Aluminum Dual Platform ladder.

9:42 a.m. — Crooks exits the Home Depot. Video footage of the parking lot reportedly shows him leaving in a vehicle, although the footage could not identify the make and model of the vehicle.

10:30 a.m. — Two local law enforcement snipers are in position on the second floor inside the AGR building.

5:10 p.m. — Crooks is first seen by one sniper (AGR sniper 1) at the AGR building.

5:14 p.m. — AGR sniper 1 takes pictures of Crooks.

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Thomas Mathew Crooks

A sniper took pictures of alleged gunman Thomas Mathew Crooks on July 13, 2024, in Butler, Pennsylvania. (Sen. Ron Johnson's Office)

5:28 p.m. — AGR sniper 1 takes a picture of a bicycle and what appears to be two bags near the AGR building, although it is unclear what happened to the bicycle and bags after the day of the shooting.

 5:32 p.m. — AGR sniper 1 observes Crooks looking at his phone and using a rangefinder.

5:38 p.m. — AGR sniper 1 messages the "Sniper Group" about Crooks.

5:40 p.m. — AGR sniper 1 is instructed to "call into command" about Crooks.

5:41 p.m. — AGR sniper 1 calls into command and offers a description of Crooks and the rangefinder, and says Crooks was "lurking around [the] AGR building."

5:49 p.m. — Photos of Crooks were sent to Butler County Emergency Services Command.

5:55 p.m. — Butler County Emergency Services confirms the photos were received.

5:59 p.m. — Butler County Emergency Services asks which direction Crooks is moving. AGR sniper 1 is initially unsure which direction Crooks is moving.

6:05 p.m. — AGR sniper 1 later says Crooks has a backpack and is moving northeast "in the direction of Sheetz."

Bike and bags

A sniper took a picture of a bike and what appeared to be two bags located near the American Glass Research building on July 13, 2024, in Butler, Pennsylvania. (Sen. Ron Johnson's Office)

6:06 p.m. to 6:12 p.m. — AGR sniper 1 moves to the ground floor of the building to meet local law enforcement patrol to notify them of Crooks' presence.

Roughly 6:11 p.m. — Crooks start to open fire, and the Secret Service then returns fire and kills Crooks.

6:23 p.m. — Beaver County SWAT operators step onto the roof where Crooks was stationed and confirm he is dead. Local law enforcement from another county and at least one Secret Service agent also walked onto the roof.

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6:46 p.m. — Crooks is patted down when law enforcement finds a transmitter device, Crooks' phone and the rangefinder in his pockets.

7:45p.m. to 7:46 p.m. — As requested by the Allegheny Bomb Squad, local law enforcement sent pictures of Crooks and the items to an ATF agent. The ATF is reportedly using the pictures of Crooks to run facial recognition.