Over the weekend, another incident occurred in the slew of brutal zombie apocalypse attacks. The 22-year-old Jeremiah Haughee's cannibalistic behavior was initially blamed on bath salt use, but experts say this may not be the case, Examiner reports.

Early Saturday morning, a Florida family woke up to find Haughee naked on their roof before attacking and biting the homeowner. It took police five hours to subdue the attacker, who continued to fight emergency and hospital personnel with unusual strength.

St. Augustine Police Department spokesman Mark Sampson said it is likely that the 22-year-old ingested a type of hallucinogenic drug, but it hasn't been confirmed that bath salts prompted the bizarre behavior. Sampson said the attacker was exhibiting symptoms of a new phenomenon known as Excited Delirium.

Obviously, any prudent person would realize this suspect was out-of-control of his faculties, and far beyond just a normal drugged or drunken state, Sampson said. He took a butt-whipping from officers, but just kept on coming, which is typical of Excited Delirium. Our officers did what they were trained to do to prevent him from further injuring himself or others.

Sampson also said Haughee inflicted on the homeowner removed a chunk of flesh from the victim's stomach, according to Examiner.

These individuals who are in a state of Excited Delirium seem to feel no pain and have extraordinary strength and endurance, the St. Augustine police spokesman said. Other signs of ED include an elevation in body temperature due to ingestion of an unfamiliar substance.

This is one reason they feel the need to pull off all their clothes, because the body is sending a message that they need to cool down, Sampson said. Everyone's system is different, and people in the medical field know this is the reaction of some individuals to a substance they breathe or ingest.

What has been dubbed as the zombie apocalyptic behavior, which includes biting, inexplicable strength and incoherent screaming, is caused by an elevated dopamine level and heat shock proteins. When this happens, the brain fails to process correctly and creates a manic or psychotic state in some individuals.

They're locked in a medical nightmare, but without training, arriving officers are likely to view them and their threatening behavior as a criminal problem, said PoliceOne, Lt. David Nickels of the Appleton, Wisconsin patrol division according to Examiner.

Excited Delirium is typically associated with drugs such as cocaine, methamphetamine and PCP, but has more recently been caused by bath salts and K2, the fake marijuana substance. According to ExcitedDelirium.org, the disorder has attracted attention over the past decade due to the sudden and seemingly inexplicable deaths of highly agitated subjects held in police custody.

Law enforcement instructional website officer.com says that there are an estimated 50 to 125 in-custody deaths in the United States related to the condition.

The infamous zombie attack in Miami that spurred the cannibalistic craze was thought to be caused by bath salts, but no trace of the substance was found in attacker Rudy Eugene's system. This was one of many incidents related to the drug to occur within the past month, such 31-year-old Carla Murphy who smoked bath salts and attacked the maternity ward staff at Pennsylvania's Altoona Regional Hospital earlier in July. A man believed to be on synthetic marijuana reportedly ate his 40 pound family dog at the end of June.