PCP can come in chunks, crystals, powder, tablets or liquid. Authorities believe Rivera and Thomas both smoked wet, which is made when a leafy substance--feasibly marijuana, tobacco, tea leaves, oregano--is rolled in paper and dipped in liquid PCP.
The effect of the drug mimics the effects of schizophrenia, including hallucinations, extreme stress, delusions and disordered thinking, according to NIDA.
"How psychotic can somebody get? Probably as psychotic as anyone with schizophrenia," Dr. Igor Galynker told ABCNews.com. Galynker is a psychiatrist and director of the Family Center for Bipolar in New York.
"The thing that sets it apart is it's a dissociative drug," Doering said. "It dissociates your mind from your body and people have out-of-body experiences and not in a pleasant sort of way."
While Doering was shocked by the horrific killings of the children, he was not shocked to hear that the killers may have been on PCP.
The experts also said that it is likely that the dangers of existing mental disorders could be exacerbated by the drug.
"I would imagine that it can precipitate psychosis in people who are already vulnerable to it," Galynker said. Authorities have said that Thomas, who decapitated her son, had a history of mental disorders. The prosecutor's office did not know if Rivera had any history with mental issues.
PCP can even do permanent damage.
"If somebody is vulnerable, it would be possible for somebody to smoke it once or twice and develop psychosis that could last months, years or could not be resolved," Galynker said. "It makes people psychotic and I don't understand why anyone would ever use it."
In terms of whether something could have been "added" to a particular batch of PCP in Camden, Galynker said it is possible that the batch had something added that made people hallucinate in a certain way, while Doering pointed out that all PCP is, by definition, "contaminated."
"It's contaminated in that it's not a pharmaceutical drug, not one that's been tested for its safety," Doering said. "A lot of these drugs are made in clandestine labs by people who probably flunked out of organic chemistry and that means that their end product isn't always going to be 'pure' or what the person thinks it was supposed to be."