A video captured by the body cameras of two cops in southern Illinois last month reportedly shows a naked man, allegedly high on the drug flakka, violently thrashing around his home, flipping over furniture, banging into walls, yelling, and avoiding all attempts by police to subdue him.

The two police officers used stun guns to try to get control of Stephen Berkeley, 51, whom they say was in a state of "excited delirium" caused by the drug — symptoms include agitation, anxiety, high body temperature, and hallucinations — and called for medical assistance, according to police chief William Southerd of Christopher, Illinois.

But it was too late, Southerd said. Berkeley died of an overdose. An investigator at the scene noted the bruises on Berkeley's body and the two officers nearby, and said the death would have been suspicious if not for the body camera videos showing Berkeley's demeanor, Southerd said.

"This video was like something I've never seen before," Southerd said. "The guy was completely going nuts in the bedroom, banging into walls, flipping things over. He completely tore the room up, and once they got him subdued he died."

"If it wasn't for the body cameras I'd probably have two officers in jail right now," he added. "Even our crime scene guys came in and said I've got a room completely torn up with bruises all over [the deceased], and two officers. I wouldn't know how to rule this."

Southerd declined to share the video with VICE News, citing privacy concerns of Berkeley's family, but hopes to eventually secure its release and use it as an educational tool to alert legislators and school authorities to what he says is the growing threat of flakka, which he described as "bath salts on steroids."

Flakka is a type of synthetic cathinone, just as bath salts are. On the death certificate issued by the Franklin County medical examiner, Berkeley's death was classified as "overdose by bath salts," showing the confusion law enforcement authorities currently face in trying to determine what new drugs they are seeing in their communities, as the makers of synthetic drugs continually change their chemical compositions. The medical examiner did not immediately answer questions from VICE News on which drug, exactly, was found in Berkeley's system.

"The reaction, the best way I can describe it is, the terms my officers used is that you're dealing with a bunch of zombies, they're just completely out of their mind."

Southerd says that bath salts and synthetic marijuana — another manufactured drug with a continually-changing chemical make-up — have been around in his town, Christopher, for a few years now. Flakka just showed up two months ago, and he is worried about what he's seen. His first encounter with someone on the drug, he said, was a woman who went out onto her front lawn with a knife and began stabbing "at trees and at the air and at ghosts" before police could subdue her.

"Synthetic marijuana's been bad for two years here, and in the state of Illinois right now it is a catch-up game. Every time they make an ingredient illegal that's in this, the Chinese — that's where it's coming from — already has another analogue to put in it," Southerd said.

"It's worse than heroin, meth, all that," he went on. "The reaction, the best way I can describe it is, the terms my officers used is that you're dealing with a bunch of zombies, they're just completely out of their mind."

A woman allegedly under the influence of flakka freaks out in the middle of a busy road. (via Youtube)

Flakka is the street name for alphapyrrolidinopentiophenone (alpha-PVP), according to the National Institute on Drug Abuse, and is mainly produced in China, where other synthetic drugs are coming from, and then distributed by dealers on the ground in the US for around $3 to $5 a dose. Unlike synthetic marijuana, flakka takes the form of crystals that can be snorted, injected, vaporized, or eaten, according to the institute.

The epicenter of flakka use is Broward County, Florida, which has had 477 reported cases of flakka use in 2014. But the drug has begun to spread to other rural communities and small towns. According to the Drug Enforcement Administration, Georgia, West Virginia, Pennsylvania, Illinois, and Ohio all had high rates of flakka cases in 2013.

Paul Faulk, the director of Broward County's Addiction Recovery Center, has witnessed the explosion of the drug first hand.

"We started seeing the emergence of flakka back in September, 2014, and didn't know what it was but saw something different with the clients that were coming in," Faulk told VICE News.

Faul said that the case load of flakka patients coming into the clinic has grown from one during September, 2014, to 40 to 50 a month now. In May, he joined local law enforcement officers and community outreach groups who held an emergency press conference warning drug users to stay away from flakka.

"It's been a drain to our organization as far as resources go because they behave in a way we have never seen with drug or alcohol intake: much more aggressive, paranoid, very anxious, and that makes it very very difficult to treat them," he said.

Faulk said that there is no quick way to detox flakka users except to sedate them until they "come back to reality," and that sometimes that can take 30 days or more.

"Even after that period of 30 days they still exhibit symptoms of the drug or the brain or body's reaction to it," he said. "Colleagues in the community have said they still see erratic behavior with this community four to six months later. it all depends on the usage and the excited delirium, when the body is pretty much dying unless it gets medical intervention."

"We've been trying to protect our youth because that's where they're targeting the drug right now," Faulk said, noting that it's cheap, looks like candy, and is frequently introduced to young people by its inclusion in other drugs.

"People want to just try marijuana or think they're getting molly but it's laced with flakka," he said. "It's extremely addictive. That's why dealers are putting it in other drugs. It produces a very strong high, it's very addictive, and many victims say this drug calls me like no other drug."

Nearly all 50 states have at least some version of a ban on synthetic cathinones, according to the DEA, though changes in a drug's composition can sometimes be used to skirt the laws.

Dr. Joseph Palamar, a researcher in population health and drug use at New York University Medical Center, said he is wary that some of the coverage flakka has gotten that portrays people as turning violent and out of control is overblown.

"I think the media is focusing on outstanding cases involving flakka," he said. "Just like with synthetic marijuana, they're showing very strange cases, then the public thinks if you use flakka you're going to get crazy and break things down and maybe attack people. But they're only focusing on the strange cases," Palamar told VICE News. "I'm sure thousands and thousands of people have used flakka and didn't break into a police station."

Palamar cautioned that individuals who lose control on flakka may already have psychological issues and be on psychiatric medications, and might be addicted to other drugs like crystal meth. But for others, using a synthetic drug like flakka that mimics the stimulating effects of methamphetamines might produce an effect "like a really strong Adderall" without causing a person to fly into a violent rage.

But for Southerd and Faulk, who are working to combat flakka use on the ground, one violent rage is enough.

"Back when meth hit it ruined a lot of people's lives, but this here is worse," Southerd said. "It's so addicting, and so easy to get, and so new that a lot of police agencies and state attorneys throughout southern Illinois don't know how to prosecute it, so there are people out here making good money off of it by selling it. It's so new, and it's so frustrating."

Follow Colleen Curry on Twitter: @currycolleen