The Drug Enforcement Administration acknowledged this week that Benoit's name surfaced in an investigation before he killed his wife, son and himself. But Benoit wasn't charged, and his supply continued until at least May, a month before the murder-suicide, according to a review of records by The Associated Press.

DEA spokesman Rusty Payne said "it's ridiculous for anyone to think we could have known that anything like that could have happened."

But Benoit's mother said she is also concerned by another disclosure that police were previously aware Benoit's doctor, Phil Astin, may have been improperly prescribing medications.

Asked if quicker action by authorities could have helped her son, Margaret Benoit said in a telephone interview from her home in Alberta, Canada, "We would certainly hope so. We just don't know. We're dealing with so many things. It's incredible."

The case highlights the DEA's focus on drug traffickers rather than individual users, even when those users are star athletes and celebrities. The targets of the BALCO investigation in San Francisco, for instance, weren't the baseball players and runners who allegedly bought steroids but the distribution network that sold them.

Building those types of cases can take years.

"We can arrest and prosecute users, but they are not the target or focus of most investigations," Payne said.

Astin was charged Monday, more than a week after the killings, with improperly prescribing medications to two patients, but not Benoit. More charges are possible later.

"You don't run out and arrest a doctor for making one prescription that is questionable," Payne said. "There's just not enough evidence to arrest or bring charges. We want to bring charges that are legitimate. Cases take time."

Authorities found anabolic steroids in Benoit's home in suburban Atlanta, leading officials to wonder whether the drugs played a role in the killings that started June 22. Benoit strangled his wife and son and placed Bibles next to their bodies before hanging himself on the cable of a weight-machine, authorities said.

Some experts believe steroids can cause paranoia, depression and violent outbursts known as "roid rage." Toxicology tests on Benoit's body are not yet complete.

Heavy, long-term steroid use can cause irritability, hyperactivity and aggressive and reckless behavior, Harvard researcher Harrison G. Pope said.

"Alternatively, if you take a high dose for a prolonged period and then stop it, there is a risk of getting profound depression during the withdrawal period," he said.

A DEA agent's affidavit said Astin prescribed a 10-month supply of anabolic steroids to Benoit every three to four weeks between May 2006 and May 2007. It says that during a probe called "RX Weight Loss," Benoit was identified as an excessive purchaser of injectable steroids.

The affidavit also says that "Astin has been the subject of concern for excessive and/or suspicious prescribing activity by the Carrollton, Ga. Police Department and local area pharmacies."

Authorities have not said what "RX Weight Loss" refers to. But Benoit's name was discovered among hundreds of customers during an investigation into illegal steroid sales, according to a law enforcement official who spoke on condition of anonymity because that investigation is ongoing.

As a customer, Benoit was not a target of that probe and there was nothing differentiating him from any of the other buyers whose names surfaced, the official said.

Astin has said he prescribed testosterone for Benoit, a longtime friend, in the past but has not said what, if any, medications he prescribed when Benoit visited his office June 22, the day authorities believe Benoit killed his wife.

A spokesman for the police department in Carrollton, in west Georgia, declined to comment on any information the agency may have developed on Astin before the killings, referring questions to U.S. Attorney David Nahmias' office, which declined to comment. A manager at a pharmacy that filled Benoit's prescriptions also declined to comment.

Payne said the DEA has long known the possible side effects of steroid abuse and that is why it focuses on taking illegal traffickers off the street.

"It's a message we have to keep pounding away at," he said.

The second-guessing aside, the wrestler's mother said there's not much that can be done now except mourn her son, daughter-in-law and grandson.

"It's so late now, too late," Margaret Benoit said. "You can't turn the clock back."