Steroids experts say federal prosecutors missed an opportunity to learn more about what slugger Barry Bonds did and didn't do - and perhaps strike a memorable blow against steroid use - by failing to proceed with a trial in the case of the Bay Area Laboratory Co-Operative, or BALCO.

Now, the experts suggest, Bonds might as well wear a question mark on his back instead of No. 25.

"The whole BALCO thing leaves us in a very unsatisfied situation," said Gary Wadler, a New York University medical professor and an expert on drugs in sports.

Four defendants reached plea agreements this summer after an investigation of BALCO, a California company suspected of selling banned, performance-boosting drugs. The agreements mean there will be no BALCO trial - a trial, experts said, that could have forced witnesses to disclose details about distributing steroids to star baseball players and other athletes.

Bonds - who goes on the road for the first time this season when his San Francisco Giants play the Nationals tonight - was not charged in the BALCO case, but his personal trainer was. The trainer, Greg Anderson, pleaded guilty on July 15 to conspiracy to distribute anabolic steroids, and to money laundering. BALCO president Victor Conte pleaded guilty to the same charges.

Steroids experts had hoped a trial would reveal more about Bonds and further educate the public about how widespread steroid use might be in sports.

"We were all looking for the exclamation mark on this whole sordid affair, and we're still left with conjecture," Wadler said.

Wadler said a trial could have gotten closer to the truth about what substances Bonds did or did not take. Even without a trial, Bonds' legacy will always include discussions - and whispers - about possible steroid use, the physician said.

"People have asked whether he should have a syringe or a pill or an asterisk next to his name," Wadler said. "That's a moot point. The public already has strong opinions about Barry Bonds and his performance."

Even without a trial, prosecutors said the BALCO investigation served an important public purpose.

'This investigation has helped reveal how the use of anabolic steroids and performance-enhancing drugs can be surprisingly dangerous and harmful," U.S. Attorney Kevin V. Ryan said in a prepared statement.

Federal sentencing guidelines - which some prosecutors and experts have called too weak - did not appear to give Ryan much leverage. None of the four BALCO defendants is expected to receive more than a year in prison. Prosecutors have recommended that Conte - who had once said he was "willing to reveal everything" he knows - receive four months in prison and four months home detention as part of his plea. His sentencing is Oct. 18.

The BALCO case began with so much promise but is ending without delivering the goods, said Penn State University steroid expert Charles Yesalis, who, like Wadler, has testified before Congress about steroids.

"I was tremendously disappointed in the closure of the BALCO situation," Yesalis said.

Yesalis said the public apparently needs to be shocked into believing, as he does, that steroid use is more widespread than has been revealed so far.

"Some major stars need to go down embarrassed in a court of law so sycophant moms and dads who live in Disney World have to face reality and realize how widespread this is," Yesalis said.

"You cannot take difficult action against a major societal problem unless there is unequivocal agreement that there is a serious problem."

Bonds appeared before the BALCO-investigating grand jury in late 2003. He told the grand jury that he had never knowingly used steroids but that his trainer gave him what he thought was flaxseed oil, according to the San Francisco Chronicle.

Bonds was given a pass in March when a congressional committee decided not to subpoena him along with other players for a hearing on steroids in sports. The committee's staff said they worried Bonds' presence would create a media circus and that they didn't know if the player would have anything illuminating to say.

jeff.barker@baltsun.com