Jun 29 2012

Causeway Killer Mystery

I wrote previously about the case of Rudy Eugene, the “Causeway Cannibal” who was found by police naked chewing on the face of a homeless man. At the time I felt the most plausible hypothesis for this bizarre and violent behavior was drugs, especially given that Eugene had no history of violence. It was therefore a little surprising when¬†the official toxicology report came out Wednesday showing only marijuana in Eugene’s system, and no other known street or prescription psychoactive drugs – no LSD, bath salts, cocaine, narcotics, benzodiazepines, or barbiturates.

So what are we to make of this? We now have a neuropsychiatric mystery – what can cause a man with no history of violence to do what Eugene did. According to reports he parked his car on the beach, then walked back to Miami, stripping off his clothes along the way. He had his bible with him and he tore out pages leaving them along the road as well. At one point he was seen swinging naked from a light post. He then came upon Ronald Poppo, subdued him, tore off his clothes, and then proceeded to chew off his face (but not swallow the tissue). When confronted by an armed police officer Eugene refused to stop his behavior and was then shot four times until he was dead.

If we treat this as a medical history, then what is our differential diagnosis? Before we discuss cause (etiology) we should discuss phenomenology – what kind of behavior is this? ¬†There are two phenomena to consider, psychosis vs delerium. Delerium or encephalopathy refers to an acute process that causes the higher cognitive functions of the brain to be compromised leading to a “clouded sensorium,” meaning that the person has difficulty attending to sensory information. They interact intermittently with their environment and usually also have a waxing and waning level of consciousness. They are confused as to their situation. They may hallucinate, and may become violent, but that violence is usually not directed or purposeful, just a non-specific lashing out at things around them.

The reports and video of Eugene’s behavior do not fit very well with encephalopathy. I can’t say it is impossible, but the purposeful and bizarre violence is atypical. Neurological events (such as a seizure, stroke, amnestic episode, or metabolic derangement) would cause a delirium rather than psychosis.

This episode fits better with psychosis, in which bizarre behavior is typical. Those suffering from a psychotic break may be alert and purposeful and able to interact with their environment, but have an acute thought disorder. Hallucinations (both audio and visual) are common, as are delusions, which may be elaborate and are often paranoid in nature. Directed violence is definitely possible.

Given the descriptions of the behavior that we have, I strongly lean towards psychosis as the phenomenon, rather than delirium. What, then, can cause psychosis?

There are two main causes of psychosis to consider, a psychiatric illness or drug induced. Those with schizophrenia, for example, can have episodes of rapid and severe worsening where they have a “psychotic break” and can engage in extreme bizarre and violent behavior. Such psychotic episodes can be spontaneous or triggered, by going off of anti-psychotic medication, using recreational drugs, or a psychological stressor.

I have not been able to find any definitive information about Eugene’s psychiatric history, but in the interviews with those who knew him there is no discussion of any significant psychiatric history or diagnosis, and no prior episodes of violence, hallucinations, delusions, or psychotic breaks. Now we also have a toxicology report that is completely negative – so there does not appear to be any data supporting either main cause of a psychotic episode. Where does that leave us?

I see several possibilities. The first is that Eugene did have a psychotic disorder, but was generally high functioning and just did not have any prior dramatic episodes (at least that we know about). This simply could have been his first major psychotic episode. He was 31 years old, which is a little old for a first episode but within the range that is seen. At this point the only way to determine if this was the case is for a psychiatrist to take a careful history from his friends and family in search of more subtle signs of a prior psychotic illness that was simmering in the background. However, now that Eugene is dead it is not likely that a definitive answer can be had.

The other possibility is that Eugene (with or without an underlying tendency for psychosis) did use a street drug that triggered an acute psychotic episode. The toxicology can only test for known substances, but the purpose of designer street drugs is to keep one step ahead of regulation by frequently coming out with new chemicals. Obviously it’s hard to prove that Eugene did not have an unknown drug in his system, but it’s important to recognize that this has not been ruled out by the toxicology. I hope they kept sufficient tissue samples of Eugene so that if new street drugs come to light in the near future they can go back and test him for it.

The toxicology did find marijuana in his system. This is certainly not a typical episode from just marijuana use, but I guess a third possibility (but I would say far less likely) is that Eugene had an atypical response to marijuana (which can rarely occur).


The cause of the Causeway Killer’s (or Cannibal, depending on your preference) behavior may never be known, but I think I covered all the plausible possibilities above. Of course there are an unlimited number of implausible possibilities – alien mind control, an unknown zombie virus, demonic possession, evil fairies, vampirism, etc. I do hope the authorities will continue to pursue an answer, which may turn out to be very informative.

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