Laboratory tests have detected only marijuana in the system of a Florida man shot while chewing another man's face, the medical examiner said, ruling out other street drugs including the components typically found in the stimulants known as bath salts.
There has been much speculation about what drugs, if any, would lead to the bizarre behaviour that authorities said Rudy Eugene exhibited before and during the gruesome attack that left the other man horribly disfigured.
A Miami police union official had suggested that Eugene, who was shot and killed by an officer, was probably under the influence of bath salts. The Miami-Dade County Medical Examiner said that the toxicology detected marijuana, but it did not find any other street drugs, alcohol or prescription drugs. Eugene also tested negative for adulterants commonly mixed with street drugs.
The department ruled out the most common components found in bath salts, which mimic the effects of cocaine or methamphetamine and have been associated with bizarre crimes in recent months. An outside forensic toxicology lab, which took a second look at the results, also confirmed the absence of bath salts, synthetic marijuana and LSD.
An expert on toxicology testing said that marijuana alone was not likely to cause behaviour as strange as Eugene's. "The problem today is that there is an almost an infinite number of chemical substances out there that can trigger unusual behaviour," said Dr Bruce Goldberger, professor and director of toxicology at the University of Florida.
Dr Goldberger said that the medical examiner's office in Miami is known for doing thorough work and that he was confident they and the independent lab covered as much ground as possible. But it's nearly impossible for toxicology testing to keep pace with new formulations of synthetic drugs.
"There are many of these synthetic drugs that we currently don't have the methodology to test on, and that is not the fault of the toxicology lab. The challenge today for the toxicology lab is to stay on top of these new chemicals and develop methodologies for them, but it's very difficult and very expensive." Dr Goldberger said. "There is no one test or combination of tests that can detect every possible substance out there."
An addiction expert said she would not rule out marijuana causing the agitation. "It could have been the strain of marijuana that increases the dopamine in the brain, such as sativa," said Dr Patricia Junquera, assistant professor at the Department of Psychiatry at the University of Miami Miller School of Medicine.
She also suggested that if Eugene had a mental disorder, "the marijuana could have increased even further the dopamine levels and aggravated the situation. So that can't be ruled out."
It is not clear what led to the May 26 attack on Ronald Poppo, a 65-year-old homeless man who remains in hospital. Eugene's friends and family have said he was religious, not violent and that he didn't drink or do drugs harder than marijuana.