Two times in one week, Palm Beach County Sheriff's deputies were confronted with rampaging men who tore off their clothes, shouted gibberish and fought with "super human" strength against all attempts to stop them.
The cases – which happened within four days of each other and left one dead, three injured and a 17-year-old facing a host of charges – may have more in common than their bizarre details, authorities say. They may have also both been triggered by a rare brain malfunction.
Authorities have said both outbursts could have been attributed "excited delirium syndrome." Frequently fatal, the condition is often, but not always, brought on by stimulants like cocaine and methamphetamine, or by mental illness. Less commonly, experts say, it can strike people who are under high stress and not getting enough sleep.
"This is a potentially life-threatening situation," said Dr. Deborah Mash, a University of Miami professor who has studied the syndrome for more than 20 years. "It's very serious. The police are at high risk, as is the individual and anyone else in the vicinity of this individual."
Why it happens to some and not others isn't known. But Mash believes it's linked to genetics.
The recent rampages of 28-year-old Anesson Joseph, who died after deputies ended his violent Delray Beach spree by firing shots at him, and 17-year-old Conrad Hopper, who survived a similar episode in suburban Lake Worth, fit the profile of excited delirium, according to experts.
Researchers say the syndrome impacts the brain, causing hallucinations and irregular breathing and heartbeats, and temperatures that soar as high as 107 degrees – explaining why stripping off clothes is one of its trademarks. It leads people on crazed, feverish and paranoid rages, putting everyone around them in danger.
The number of people who experience the condition is not tracked by any medical or law enforcement establishments. In fact, some groups, including the American Civil Liberties Union, question whether it even exists. They point out it is often cited in deaths that happen after law enforcement gets involved, calling it a scapegoat for excessive force.
Still, in recent decades, excited delirium syndrome has been more commonly accepted as a condition by law enforcement agencies, doctors and medical examiners.
Some law enforcement officers train for it, including those at the Palm Beach County Sheriff's Office.
At least seven autopsies completed over the last 10 years by the Palm Beach County Medical Examiner's Office cited the condition as the official cause of death. Broward County had two cases that used the term during the same time frame.
Excited delirium can turn fatal, doctors say, when a person's body can't handle its dangerous symptoms.
"The rapid heartbeat, the excessive temperature and so on is totally out of control," said Dr. Nabil El Sanadi, chief of emergency medicine at Broward Health. "And it literally leads to their death."
He said he's seen several cases of excited delirium over the years. People suffering from it come into the emergency room with rapid heart rates, high blood pressure and feverish temperatures. They act on instinct alone and believe everyone around them is a threat.
"It's like an animal that's cornered," El Sanadi said. "They don't care about themselves – they fight to the death. That's exactly what happens: their disinhibited, animalistic instincts basically are turned on."
Stephen Hauss feels lucky to be alive after a suspected case of excited delirium transformed him into a violent, nearly-naked aggressor during Memorial Day Weekend 2013.
The 23-year-old West Palm Beach man said he woke up handcuffed to a hospital bed with no idea how he got there. He couldn't believe it when he found out.
According to a Sheriff's Office report, Hauss crashed his Volkswagen into a light pole north of Royal Palm Beach, then got out and ran around, trying to pull other people out of their cars. A deputy found him stripped down to a pair of underwear, rolling in several inches of water, and tried to calm him down.
Before help arrived in the form of a bystander and other deputies, Hauss tackled the deputy, punched him, grabbed his radio and reached for his gun holster.
"For the first couple of months, I read the police report like three times a day trying to remember, but I just couldn't even imagine myself doing that," Hauss said. "If you ask anybody that knows me, I'm a quiet guy. I go to work, come home, I hang out with my friends – I'm not an aggressive guy. I'm not crazy."