A private investigator from Pennsylvania is alleging that President Donald Trump’s would-be assassin, Thomas Matthew Crooks, was not acting alone — and that there may be others planning to pick up where he left off.

Doug Hagmann told the New York Post that he and six others have been investigating the case since shortly after the shooting at the rally in Butler, Pennsylvania, on July 13 — and said that after interviewing over 100 people, they were convinced that a “criminal network” had played a role in the attempt.

“We don’t think he acted alone. This took a lot of coordination,” Hagmann said. “In my view, Crooks was handled by more than one individual and he was used for this [assassination attempt.] And I wouldn’t preclude the possibility that there were people at the rally itself helping him.”

Hagmann also alleged that the FBI might be withholding information about the case, telling the Post that he’d been shown the door several times — by either security personnel or federal agents — as he attempted to carry out his investigation.

“One can assist in an operation like this by omission or standing down. There are people still out there involved in this case that need to be brought to justice,” he said.

According to Hagmann and his team, location data — from electronic devices that were geolocated with Crooks at multiple points leading up to the shooting — don’t add up. At least one device geolocated with Crooks that day is still pinging at a local high school, Hagmann claimed.

Rep. Clay Higgins (R-LA), who served on the bipartisan task force investigating the attempted assassination, says he believes Crooks acted alone. He did agree with at least one of Hagmann’s claims, however, saying that the FBI was more of a hindrance than a help to his investigation as well.

Higgins’ theory, rather than a conspiracy involving a “criminal network,” is that drugs ultimately played a role in pushing Crooks over the edge.

“Something happened to make him go crazy and that’s why I think it might have been pharmaceuticals. He performed an attempted assassination and he was committed all the way through – to death. He was not acting erratic but he was a wild lunatic at the same time, incredibly calculating and incredibly smart,” Higgins told the Post.