When filming a realistic violent music video out in public, it's probably best to tell the authorities first.

The Los Angeles County Sheriff's Department received a call about a suspected kidnapping on Wednesday, which they posted on their Facebook page on Friday night.

Police said a driver was traveling on Highway 39 in the San Gabriel Mountains when they called the San Dimas station to report what they believed was a kidnapping in progress. The witness saw two men pointing a gun at another who was tied and immobilized with duct tape near a black BMW. 

(Los Angeles County Sheriff's Department)

Deputies were called to the scene and conducted a “high risk” traffic stop on the vehicle, according to a written statement. Police detained three men during the investigation and determined they were just filming a music video. The only problem was they were using a real firearm.

Duct tape and real firearm used in music video mistaken as kidnapping

Duct tape and real firearm used in music video mistaken as kidnapping (Los Angeles County Sheriff's Department)

In the Facebook post, police advised, "If you are going to be filming your music video up in the mountains this weekend, please do not do the following: Pretend to kidnap and duct tape your victim, victim pretending to break free and getting out of trunk, have a shovel, use a handgun."

BODY OF GIRL WEARING 'FUTURE PRINCESS HERO' SHIRT FOUND ALONG TRAIL; POLICE SEEK HELP IN IDING VICTIM

“That way we can at least pass by or make sure if anyone calls on it, let them know it’s just a movie shoot,” Deputy Ed Luna told the New York Times.

Because they had a real gun, one of the men was arrested for a misdemeanor weapons charge.

Sgt. Michael McGrattan told the New York Times on Friday that police had to be on alert due to previous incidents in the area.

“Typically on a call like that, we would send multiple deputies,” McGrattan said. “That’s actually a remote location up in the mountains. Up in the mountains there, we actually from time to time, we have bodies dumped, we have had shootings, we have had murders.”

On Facebook, police joked, "Mental note: book a place to film your music video! Maybe advise the cops first?!"