For 19 years, Marty McClain has been in a race against time.

As the clock ticks, he knows that a client is approaching death.

It is frustrating and depressing work.

''But I can't give it up,'' said McClain, a lawyer for 12 Death Row inmates. ``I've known some of these men for more than 14 years. They're more than just clients, they're human beings.''

Some would argue their crimes are inhuman. McClain's clients include:

• Gerald Eugene Stano: On Death Row for the murders of 10 women and girls. He once sought credit for 31 more.

• Thomas Provenzano: On Death Row for a 1984 Orange County courthouse shooting rampage that left 61-year-old bailiff William Wilkerson dead and two others paralyzed.

• Michael Rivera: On Death Row for the 1986 slaying of 11-year-old Staci Jazvac in unincorporated Broward.

McClain knows his is an unpopular cause.

''Part of the reason I do what I do is that I'm motivated by the challenge and the other part is that someone has to do it,'' McClain said. ``Someone needs to take up that side of the judicial system and argue it. I feel the obligation to hold the state to its proof.''

There have to be checks and balances in the system, he said.

''There's always two sides to every story,'' he said. ``I always look for that side of my client. I make him a human being who made mistakes but is still a human being.''

The state-funded agency that McClain works for -- Capitol Collateral Regional Counsel, which represents men and women on Florida's Death Row -- is not about money.

The pay is lousy. He receives a flat fee of $69,000 for a case that could drag on for years.

It's not about easy hours. His day begins at 7 a.m. and often ends about 10 p.m. He often works 60 to 70 hours a week.

He knows he's missed out on many things in life -- a wife, family, a decent salary.

''I don't regret those choices,'' he said.

McClain recalls cases and facts with precision when planning courtroom strategy.

''I always have to be aware that the next step for my client may be federal court,'' McClain said.

``I have to be aware of all the federal laws and statutes. It's like a 3-D chess game.''

McClain doesn't give up on his clients, said Richard Deiter, executive director of the Washington-based Death Penalty Information Center.

''He goes the extra mile,'' Deiter said. ``He won't stop until every stone has been turned.''

The proof is in his work. McClain has had several clients exonerated, making him a rarity among Death Row lawyers.

McClain believed in the innocence of Frank Lee Smith. He requested DNA testing and found an eye witness who recanted her testimony after initially identifying Smith as the killer. The Fort Lauderdale man died in January 2000, 11 months after DNA testing proved he did not commit the 1985 rape and murder of an 8-year-old girl.

McClain has claimed victory in two other cases:

• Jan. 3, 2002: Juan Melendez was released from Death Row after serving 17 years for a murder another man claimed to have committed.

• Jan. 24, 2003: Rudolph Holton was released after 16 years on Death Row because of a prosecutorial mistake and DNA evidence.

One of McClain's assets is his ability to write more like an author than a lawyer, said Larry Spalding, of the American Civil Liberties Union.

''When you read a Marty McClain brief, you read a story,'' Spalding said. 'He will start off with a phrase like: `Melendez was born in a poor hamlet to a mother who . . .' It's like a good novel.''

It was by chance that McClain found his way to Florida after graduating from Wyoming Law School in 1980.

Back then, Florida relied on private attorneys to represent death appeals. Cases were being overturned and finding competent lawyers proved difficult.

In 1985, Attorney General Jim Smith suggested to Gov. Bob Graham that the governor create an office to handle all Death Row appeals.

Graham agreed.

Capitol Collateral Representative was born with Spalding as its director. The agency was split into three regions in 1998 and renamed Capitol Collateral Regional Counsel: Tallahassee, Tampa and Miami. The Miami office since has been moved to Fort Lauderdale.

Spalding advertised in national legal journals hoping to attract hungry, idealistic young lawyers. McClain, then 33, was working for the statewide public defenders office in Wyoming.

He quickly signed on.

''We wondered at the time if we were bringing in a cowboy from Wyoming, but he had good credentials,'' Spalding said.

Things changed when Bob Martinez was elected governor a year later. Death warrants soon began piling up.

''Sometimes we had 12 or 14 clients with scheduled executions at one time,'' McClain said. ``Martinez's purpose was to keep pressure on lawyers, keep us in a pressure cooker and bogged down in litigation.''

He left the agency in May 1990. A year later, he was back, when Lawton Chiles was elected governor.

In 1997, McClain began one of the most difficult fights of his career. He challenged the constitutionality of Florida's electric chair, a fight that went all the way to the U.S. Supreme Court.

In 2000, before the court could rule, Gov. Jeb Bush signed laws making lethal injection -- not the electric chair -- the primary execution method.

The change came too late for McClain's client, Leo Jones, convicted of shooting a Jacksonville police officer in 1981. Jones was electrocuted in 1998.

''His death was really hard for me because I truly believe he was innocent,'' McClain said.

``I had to call him a few hours before the execution and tell him he was going to die. That there was nothing more I could do.''

He finds some comfort in his role in abolishing Florida's electric chair. And of course there are Melendez, Holton and Smith.

''That's why I keep doing it,'' McClain said. ``For them.''