It wasn't bath salts.

According to a statement on the full toxicology report by the Miami-Dade medical examiner, the only drug detected in the lifeless body of infamous Miami face-chewer Rudy Eugene was marijuana.

"The department's toxicology laboratory has identified the active components of marijuana," medical examiner Dr. Bruce Hyma said in a statement. "The laboratory has tested for but not detected any other street drugs, alcohol or prescription drugs...This includes cocaine, LSD, amphetamines (Extasy, Meth and others), phencyclidine (PCP or Angel Dust), heroin, oxycodone, Xanax, synthetic marijuana (Spice), and many other similar compounds."

A second forensic toxicology lab also confirmed the absence of the most common ingredients of bath salts, a synthetic amphetamine cocktail blamed in several recent incidents that bear some similarity to Eugene's attack.

"Within the limits of current technology by both laboratories," the statement read, "marijuana is the only drug identified in the body of Mr. Rudy Eugene."

The statement did not address previously reported autopsy findings of what appeared to be undigested pills in Eugene's stomach, and an expert told the Associate Press marijuana alone was not likely to cause such an attack:

"The problem today is that there is an almost an infinite number of chemical substances out there that can trigger unusual behavior," said Dr. Bruce Goldberger, Professor and Director of Toxicology at the University of Florida.

Goldberger said that the medical examiner's office in Miami is known for doing thorough work and that he's 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.

"...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." Goldberger said. "There is no one test or combination of tests that can detect every possible substance out there."

The medical examiner's office did not immediately respond to requests for comment.

Eugene, 31, was widely speculated to have been on some form of synthetic drugs or suffering a drug-induced psychosis the afternoon of May 26 when he stripped naked and brutally attacked homeless resident Ronald Poppo in broad daylight along Miami's busy MacArthur Causeway, chewing and ripping off roughly half of the older man's face.

A police officer responding to multiple 911 calls shot and killed Eugene as he crouched over Poppo, reportedly refusing to stop the gruesome assault by growling at the officer with Poppo's flesh in his mouth.

The 18-minute attack and its aftermath were captured on surveillance video from the Miami Herald's parking garage, but it is still unknown what prompted Eugene to commit such a horrific crime.

According to Local10, the former North Miami Beach High School football player was once diagnosed as schizophrenic after an arrest, but authorities are not sure if he ever sought treatment.

Records show Eugene had been arrested 8 times since the age of 16, including 4 instances involving marijuana. But though he was once accused of threatening to kill his mother, friends and family members alike say they never expected such violence from Eugene, who was participating in a Bible study, reading the Koran, and telling friends he wanted to stop smoking marijuana.

"There's no answer for it, not really," Eugene's younger brother, Marckenson Charles, told the AP. "Anybody who knew him knows this wasn't the person we knew him to be. Whatever triggered him, there is no answer for this."

Poppo, meanwhile, is doing "well," according to doctors at Jackson Memorial Hospital's Ryder Trauma Center. The 65-year-old has lost one eye, is missing his nose, and faces a string of surgeries to repair his wounds and reconstruct his face.

"We have mental health professionals to help him with the coping, and he's coping remarkably well," said plastic surgeon Dr. Wrood Kassira.

HOW YOU CAN HELP: The Jackson Memorial Foundation has set up a fund to assist Ronald Poppo in his recovery, which experts in facial reconstruction have said will include lengthy treatment, staged reconstruction, and psychological care. Donations can be made online at jmf.org.

WARNING: SLIDESHOW CONTAINS GRAPHIC PHOTOS:

Loading Slideshow...
  • Rudy Eugene

    Rudy Eugene poses for a picture in this undated photo. Eugene was shot to death by Miami police as he crouched over Ronald Poppo's limp body, naked and growling, chewing off chunks of the man's face. (Miami Herald/MCT via Getty Images)

  • Rudy Eugene

    A photo of Rudy Eugene as happy young toddler. Eugene was shot to death by Miami police as he crouched over Ronald Poppo's limp body, naked and growling, chewing off chunks of the man's face. (Miami Herald/MCT via Getty Images)

  • Rudy Eugene

    A photo of Rudy Eugene as happy young toddler. Eugene was shot to death by Miami police as he crouched over Ronald Poppo's limp body, naked and growling, chewing off chunks of the man's face. (Miami Herald/MCT via Getty Images)

  • Rudy Eugene

    A photo of Rudy Eugene as happy young toddler. Eugene was shot to death by Miami police as he crouched over Ronald Poppo's limp body, naked and growling, chewing off chunks of the man's face. (Miami Herald/MCT via Getty Images)

  • Ronald Poppo At Stuyvestant High

    Ronald Poppo <a href="http://www.huffingtonpost.com/2012/05/30/ronald-poppo-face-eating-victim-miami-stuyvesant-high-school_n_1556692.html?utm_hp_ref=rudy-eugene" target="_hplink">attended New York City's prestigious Stuyvesant High School</a> before becoming homeless and lost to his family for decades.

  • In a <a href="http://www.huffingtonpost.com/2012/06/12/ronald-poppo-face-chewing_n_1590459.html" target="_hplink">photo released June 12</a>, Ronald Poppo walks with assistance at Jackson Memorial Hospital.

  • A photo <a href="http://www.huffingtonpost.com/2012/06/12/ronald-poppo-face-chewing_n_1590459.html" target="_hplink">released June 12 by Jackson Memorial Hospital</a> shows progress treating Ronald Poppo's horrific injuries.

  • A City of Miami police officer stands watch near the scene where a naked man, far right, was shot dead on the MacArthur Causeway ramp onto Northeast 13th Street in Miami on Saturday, May 26, 2012. A witness said the naked man continued to chew on the face of another naked man on a Miami highway ramp and growled when a police officer tried to stop him. The victim remained hospitalized Monday. (AP Photo/The Miami Herald, Marsha Halper) MAGS OUT

  • Crime Scene investigator Andres Betancourt photographs a credit card found at the scene belonging to Rudy Eugene, Tuesday, May 29, 2012 in Miami. Authorities were seeking more witnesses Tuesday to help explain what led Eugene, who was naked, to start chewing another naked man's face and whose only response when confronted by police was to growl and keep attacking - even after being shot by police Saturday. (AP Photo/Wilfredo Lee)

  • First responders treat Ronald Poppo after the attack.

  • This 2008 video shows Rudy Eugene in Miami-Dade bond court on charges of marijuana possession and marijuana possession with intent to distribute.

  • Rudy Eugene, undated photo

  • Ronald Poppo

  • Westbound traffic on the MacArthur Causeway, approaching the Northeast 13th Street ramp in Miami, is backed up Saturday May 26, 2012, after a police officer fatally shot a naked man on the ramp who was chewing on the face of another naked man. The victim remained hospitalized Monday. (AP Photo/The Miami Herald, Marsha Halper) MAGS OUT

  • Scene of attack

  • Rudy Eugene's Longtime Girlfriend

    Rikkia Cross cries as she talks about her relationship with Rudy Eugene.

  • Girlfriend Says Face-Chewing Attacker Was Religious

    A South Florida woman says she often read religious texts with a man who is accused of chewing off the face of a homeless man. Rudy Eugene was shot and killed by police. (June 6)

  • Gloria Allred, Yovonka Bryant

    Yovanka Bryant,left, and her lawyer, Gloria Allred, discuss a recent attack on a homeless man by Brant's boyfriend Rudy Eugene, during a news conference, Wednesday, June 6, 2012 in Miami. Bryant said she last heard from Eugene, the day before he chewed off the face of a homeless man alongside a Miami highway. A police officer shot and killed Eugene. The homeless man remains hospitalized. (AP Photo/J Pat Carter)

  • Gloria Allred, Yovonka Bryant

    Yovanka Bryant, right, and her lawyer, Gloria Allred, show a photo of Bryant and her boyfriend Rudy Eugene, during a news conference, Wednesday, June 6, 2012 in Miami. Bryant said she last heard from Eugene the day before he chewed off the face of a homeless man alongside a Miami highway. A police officer shot and killed Eugene. The homeless man remains hospitalized. (AP Photo/J Pat Carter)

  • Full 18-Minute Attack Surveillance Footage

  • Photos Released of Face-Chewing Victim in Miami

    Doctors release photos of Ronald Poppo, the 65-year-old homeless man who was the victim of a gruesome face-eating attack in Miami.

  • Miami Homeless Discuss Face-Eating Attack

    Homeless men who live near where one man allegedly ate the face of a homeless man react to the crime. (May 30)