FBI agents and sheriff’s deputies responded to businesses near Trump International Golf Club in Florida to seize surveillance video within two hours of a Secret Service agent firing at a suspected would-be assassin, according to interviews with business owners.

Authorities say Ryan Wesley Routh was lying in wait for former President Donald Trump at the West Palm Beach golf course on Sunday with a semi-automatic rifle.

The FBI has called the incident an apparent assassination attempt and Routh is accused of being a felon in possession of a firearm and for having his weapon’s serial number obliterated. He remains in custody, according to court records.

The businesses near the course and their owners did not want to be named, citing privacy reasons.

One business was visited by the FBI almost exactly within two hours of the shooting and law enforcement took the surveillance video hard drive, which may have contained images of Routh leaving the road along the Trump golf course, according to a store employee.

The time of the alleged engagement with Routh by the Secret Service was approximately 1:30 p.m. ET on Sunday, and the business says that FBI special agents and a Palm Beach County Sheriff’s Office deputy had visited the business around or just before 3:30 p.m. ET.

Another business owner who was visited by the FBI believed their business may have had surveillance video of Routh leaving the scene, and that business owner says the FBI copied the file containing the video.

When an NBC News reporter visited the business for a second time to try and obtain the video, the business owner says the FBI had deleted the file from his machine.

A third business said that agents visited them for surveillance video after the shooting.

Law enforcement experts say the FBI is likely trying to develop a timeline to determine what Routh did before and after the shooting.

Video and witness interviews can sometimes be used to develop additional information, such as who Routh may have been talking to or what he was speaking about, all potentially helpful for investigators trying to determine a motive, those experts say.

A spokesperson for the Palm Beach County Sheriff’s Office declined to comment, referring NBC News to the FBI. A spokesperson for the FBI, which is leading the investigation, also declined to comment on their investigative work.

“We appreciate your interest in this case. However, in order to preserve the integrity of the investigation, we have to decline comment," the FBI spokesperson told NBC News.

Federal charging documents allege that Routh arrived at the golf course at 1:59 a.m. ET the day he was allegedly spotted with a weapon near the course, based on FBI cell phone analysis.

What is not known publicly is how Routh parked his vehicle prior to the Secret Service shooting, nor how he got to I-95 North after the shooting.

The FBI typically takes possession of the physical electronic media in an ongoing prosecution in order to preserve the device’s metadata so it can be used in court testimony, based on a NBC News analysis of prior national security cases.

Routh’s next court appearance, which will determine whether or not he will be released pending his federal trial, is slated for Sept. 23. He has not yet been asked to enter a plea.