He gave up a lucrative career in business to help people wrongly imprisoned. He has saved four lives: so far. Daniel Jeffreys met him
"There are thousands of innocent Americans in jail," says Jim McCloskey. He is leaning forward over his desk in an office across the street from Princeton University. In front of him is a stack of files, which he thumps with a meaty fist. "These are case histories. All the people here were on death row or serving life." The pile is at least 15 folders high. "We got every one of them released."

McCloskey is the founder and president of Centurion Ministries, a charity devoted to the wrongly accused. In a room outside his office there are 10 desks for volunteers and a white board with 15 names. Most are under the heading "Lifers", but one name sits beneath two words marked in black and underlined - "Death Row". McCloskey believes that all 15 are innocent and that their cases are just the most winnable from thousands of suspect convictions. The ministry receives several fresh cases for examination every day.

The United States has never had more people in prison: latest figures from the FBI show 1.1 million at the end of June last year. The prison population has tripled since 1980 and increased by 8 per cent in the past year alone. This year the 36 states that have restored capital punishment will execute more than 100 prisoners, the first time since 1917 that there will have been that many executions.

"I estimate 10 per cent of prisoners who plead not guilty at trial are innocent," says McCloskey. "That means we probably executed at least seven innocent men this year alone."

The man is quick with his numbers. He should be - four former death-row inmates are free because of his work.

McCloskey, 53, was born to a wealthy family in a smart suburb of Philadelphia. After university he embarked on a career as a management consultant. By 1980 he was earning more than $100,000 a year.

"I was very successful and conservative. If you had told me in 1978 that there were innocent people in jail I would have mocked you.

"My life looked pretty nice on the outside, but inside I was empty. I returned to the church and began studying the scriptures. I was struck by the call of Christ. 'Follow me and I will make you fishers of men.' I decided to leave my job and enter a seminary."

His family was stunned by the decision, but McCloskey had more surprises in store. "In my second year I volunteered to be a counsellor at the New Jersey state prison. The inmates there kept telling me about this guy, George De Los Santos, who they all believed was innocent. I investigated, looked back at the files, and even without formal legal training the case looked unsafe to me."

McCloskey began to form a relationship with De Los Santos, to assess his guilt or innocence for himself. "After a while I was sure he had been framed. He'd served just five years of a 25-year sentence and was wasting away. One day in mid-December I told George I was going to give him a year of my life as a Christmas present, and during that time I would suspend my studies and try to prove his innocence."

He kept his word. A bachelor, he moved into a small flat and devoted himself to the case. Like many unjust convictions, De Los Santos had been condemned by evidence from a jailhouse witness who claimed to have heard him confess to murder. At the successful appeal hearing the judge said that the witness's statements "reeked of perjury" and that "the prosecutor knew it".

Freed from prison, De Los Santos told McCloskey of another inmate he thought had been framed. "I couldn't believe here were two in the same prison," he says. "Then I investigated and found this conviction was suspect as well, and I knew I had found a life's work."

Fifteen years later, McCloskey has created a unique organisation. He has an annual budget of $330,000, an assistant and a team of volunteers in Princeton and elsewhere. The entire budget is raised from contributions by churches, foundations and individuals. "I pay myself about $40,000 a year now - a far cry from my 1980 money, but I consider myself the luckiest man in the world. I'm a man with a mission and without that I would wither on the vine."

As would the lives of many innocent people. Until McCloskey came along, only the wealthy or the politically connected could afford protracted appeals. His door is open to every kind of person, as long as their cases meet certain criteria.

"I have to think the person is innocent, that they're worth saving and that there's a good chance we'll find something that will get them free," he says. "People are not giving us money so we can free people to go back on the street to rape or kill again."

If an inmate meets all criteria, McCloskey hits the streets. Like an old-fashioned gumshoe he hangs out in bars, knocks on doors and keeps asking questions until somebody comes up trumps.

The Clarence Bradley case was a classic. Bradley had been convicted of rape and murder in 1980. He was the black supervisor of three white caretakers at a Texas high school. Two of the three men raped and killed a white pupil and the third testified against Bradley. When the police picked Bradley up, he asked them why and they replied: "You're the nigger, so you're elected."

Bradley was sentenced to die and spent 10 years on death row before McCloskey cracked his case. "The guy who testified, John Henry Sessum, he left town, he was unemployed and drinking hard. We had to knock on a lot of doors to track him down." But they did, and Sessum was quick to confess. "He told me he had barely had a good night's sleep in 10 years."

Sessum revealed that he had seen the other two men lead the girl away and he'd done nothing. "He told me the police had intimidated him into framing Bradley." McCloskey told Sessum that Bradley was due to die in just two days. He was shocked. "He went pale and told me he'd let the girl go to her death but he would not let the same thing happen to Bradley."

Even then McCloskey had work to do. "Sessum said he couldn't testify unless his mother gave him permission to work with a 'nigger'. So he contacted her and she said she'd make an exception." Sessum's testimony reversed Bradley's conviction on the eve of his execution. The two men who Sessum says committed the rape and murder have never been arrested. "If Texas pursued the case now, they'd have to admit Bradley was framed," says McCloskey. "That would mean paying millions in compensation."

He believes that racism often plays a part in wrongful convictions, but many of his cases have involved just white people. "This is a problem that affects poor Americans, regardless of their colour. The most common factor among people who are innocent and sent away is a lack of money."

Poverty means a defendant has to accept a court-appointed lawyer, called a "public defender" in the US. "This type of lawyer is often inexperienced, underpaid and under-motivated," says McCloskey. There are 30,000 lawyers in New Jersey but only 241 are primarily engaged in criminal defence work. The New York Association of the Bar estimates that public defenders spend an average of eight hours preparing for each case.

After incompetent defence counsel, McCloskey lists four other factors that produce unjust convictions: presumption of guilt by juries; false witnesses for the prosecution; misconduct by prosecutors; and perjury by police officers. "In every one of our cases a police officer has lied at some stage," he says.

His current death row case illustrates the point. Kerry Max Cook, a white Texan, was convicted of murder 12 years ago. The victim was a young woman and Cook's fingerprint was found on her patio door. Not compelling evidence - until you have a police officer prepared to say that he found the print six hours after it had been left, which put Cook in the girl's apartment at exactly the time of death.

"Eleven years after the crime the American Forensic Association hears about this fingerprint evidence," McCloskey says. "They know you can't fix a print to the time it was left, so they contact the detective for an explanation. He writes back that he knew it was false testimony, that he knew it was unscientific but the prosecutor made him do it!"

"Cook had terrible lawyers," he says. "The lead lawyer was an ex-prosecutor from an adjacent county who had just lost his job in an election. He took the case for a few hundred dollars, plus he was a drunk to boot and he had a prosecutor's mentality. He just failed to ask obvious questions."

Cook is still on death row, awaiting an appeal hearing next year, based on new evidence found by Centurion investigators. McCloskey expects many more cases.

"Since we began this work, the conservatism in this country has broadened and deepened," he says. "We are a vengeful, bloodthirsty society and the cry is burn 'em or bury 'em. Among the public there's a hysteria towards violent crime, so the police feel pressure to clear their books and the politicians are prepared to grant more latitude."

The telephone rings in the office, even though it is a Saturday. McCloskey picks it up and starts making notes. "A guy in Arizona, set for execution in two weeks' time - we don't have much time."