Steroids were among the prescription medications found by investigators going through pro-wrestler Chris Benoit's house, where he strangled his wife and young son last weekend before hanging himself.
Key to their probe is determining whether drugs played a role in the double murder-suicide, and whether so-called "roid rage" was at the root of the tragedy.
Chronic use of anabolic steroids — the kind commonly taken in excessively high doses by athletes including wrestlers — has been linked to marked aggression and anger, or what is referred to as "roid rage."
"Anabolic steroids affect neurochemicals in the brain," said Dr. Linn Goldberg, an expert in steroid use and the head of sports medicine at Oregon Health and Science University. It's those neurochemical changes that cause the extreme anger, he explained.
Goldberg said most people who succumb to steroid-induced rage are predisposed to aggression and anger problems, and the drugs exacerbate those tendencies.
"They're not in great control to start with and then they use steroids and it heightens that," he said. "They have problems with impulse control."
Sam Maniar, a sports psychologist at Ohio State University Medical Center, said it's rare for someone who wasn't at all aggressive before taking steroids to become filled with rage just by using the performance-enhancing drugs.
"It's really hard to say what comes first — it's like a chicken and the egg type of thing," Maniar said. "There's some evidence that mood changes can occur, but sometimes people have the rage or depression there before."
Fayetteville, Ga., sheriff's spokesman Lt. Tommy Pope declined to comment as to whether the steroids found in the Benoit family home contributed to the wrestler's state of mind when he killed his family and then himself. Police were awaiting toxicology test results to determine whether or not he was on steroids or any other drugs.
World Wrestling Entertainment (WWE) issued a strongly worded statement Tuesday night condemning media speculation that steroids had anything to do with the homicides and suicide.
In addition to uncontrollable fury, other possible behavioral side effects of regularly taking large quantities of steroids include paranoia, delusions, depression and mania.
"They lead to psychotic episodes of aggression," said FOXNews.com's managing health editor Dr. Manny Alvarez. "It's not inconceivable that this wrestler was indeed suffering from some of the psychological consequences of anabolic steroids, which might have led him to commit this heinous act."
When studies have been done on rats, according to Goldberg, the rodents have become aggressive after being given steroids and frequently remain aggressive even once the drugs are no longer administered.
But he and Maniar agreed that fury so intense it becomes lethal is uncommon, even in the worst cases of steroid abuse.
"It seems like it's rare for roid rage to become deadly," Maniar said.
Psychological side effects aside, anabolic steroids cause a host of physiological problems too, including high blood pressure, heart attacks, stroke, blood clotting, kidney disease and changes in metabolism.
"In World Wrestling Entertainment, a lot of these athletes are dying at six times the rate of other human beings, most of them from cardiovascular disease," Goldberg said. "There's a bunch of them who died at young ages, in their 30s and early 40s."
Athletes of all kinds take anabolic steroids to increase muscle mass and improve performance. The problem has become so widespread in professional sports that the government has gotten involved in cracking down on steroid use.
Whether or not Benoit was abusing steroids and in the throes of roid rage when he smothered his wife and 7-year-old son and then took his own life, the tragedy has caused the problem to be revisited.
"If there's any take-away message, it's that anabolic steroids of any sort at any age have no place in any kind of professional sports," Alvarez said.