The Bureau of Alcohol, Tobacco, Firearms and Explosives say they believe that Las Vegas gunman Stephen Paddock had an accomplice at the Mandalay Bay hotel who helped him carry out the attacks.

The ATF believe that a security guard working for the Mandalay Bay Resort and Casino helped Paddock plan and execute the deadliest mass shooting in US history. reports:  Jesus Campos has been praised for his apparent heroics on October 1st, as he supposedly rushed to Paddock’s suite, was shot in the upper thigh through the door, and continued to help get people to safety despite his wounds. However, a new report indicates the ATF now believes he was likely an accomplice of Paddock’s, and may have even been involved in the initial shooting as a second gunman from the other broken window in Paddock’s 32nd-floor room.

According to an ATF official, these suspicions are corroborated by the extreme amount of gunpowder residue found on Campos’ hands. “They believe he killed Paddock, shot holes through the door and his own arm to produce physical evidence for his cover story, then went and lay next to the elevator,” a senior ATF official doing ballistic work for the shooting told GotNews.

This account would be consistent with leaked photos of Paddock’s dead body, which show casings on top of Paddock’s blood.

Such a scenario would seem unlikely if Paddock had shot himself:

Las Vegas Sheriff Joseph Lombardo has publicly said that he believes Paddock had “some help at some point.” This follows citizen journalist Laura Loomer‘s scoop that Paddock ordered room service for two people during his stay in the hotel.

Authorities have similarly been piecing together information that shines light on the sophistication of the attack. “Paddock also had an electronic signal jamming device active and that is why the cameras were all out on the floor,” the ATF official explained.

Moreover, it appears the 64-year-old multimillionaire also plotted his attack well in advance: “Paddock at a minimum scouted out two separate music concerts, one being the EDC [Electric Daisy Carnival] and the other held at the Life is Beautiful venue plaza by Fremont, but didn’t pull the trigger,” the ATF senior official told GotNews. “Paddock had big plans, and didn’t plan on dying in the hotel room.” ABC News recently reported that Paddock had previously booked a hotel room overlooking Lollapalooza, and visited other musical festivals, presumably to scout for potential targets.

“Paddock also bought 60 guns total from at least 20 different gun stores, and he only visited them each once,” the official said. The ATF is looking into the real estate investor’s mysterious background, and so far has yet to reach a conclusion. A source familiar with the investigation told GotNews he “believes [Paddock] was an illegal gun broker or possibly working for a three letter agency to catch real criminals who are trying to buy illegal guns.”

Campos could not be reached for comment, and it should be noted that initial reports are often wrong or incomplete.

Stay tuned for more.