Floridians should be grateful that Jerry Frank Townsend was not executed by their state government. Instead he spent 22 years in prison on six life sentences for rape-murders that he did not commit.

Robbing a man of much of his life is mistake enough. Worse would be a failure or refusal to learn from Mr. Townsend's tragedy -- or from the linked, posthumous clearing of Frank Lee Smith.

DNA testing cleared Mr. Townsend of several of the cases against him while reexamination of others cast doubt. Mr. Smith died on Death Row of cancer, his innocence later proven by a DNA test made at his family's behest. The DNA in these cases most probably belongs to Eddie Lee Mosley, held as incompetent to stand trial on other rape-murders.

Mr. Townsend grew up in Broward with two strikes against him -- poverty and a low IQ. What is horrifying is that he confessed to several of the crimes. Why? Because he was fed the facts and spat them back. The tapes of his confessions are replete with stops and starts and leading questions. Even so, some of what he said didn't jibe with evidence.

Indeed, that is Lesson One. Confessions (and confessions to jailhouse snitches) should be treated with great care. For 35 years, police have complained of coddling criminals because of court-dictated Miranda warnings about rights to be silent or to have an attorney present. But police techniques of intimidation and persuasion have become more subtle than rubber hoses.

Alaska and Minnesota require complete taping of confessions, which offers benefits to prosecution as well as defense. While police say that sometimes confessions are spontaneous, there was no excuse for not taping all of the interrogation of Mr. Townsend.

Lesson Two: Beware of eye witnesses. This lesson comes primarily from the Smith case. He was charged with a rape murder in the same period that Mr. Townsend was accused. Police had a description of a suspect that didn't fit him, but then the witnesses -- one of whom tried to recant -- pointed to him.

Lesson Three: Police officers should be encouraged to question, question, question even years after after a crime. Some Fort Lauderdale detectives doubted whether Mr. Townsend was guilty of one of the murders; in 1998 John Curcio pushed for DNA testing on evidence left on the victim's shorts. The test was made two years later, and the other cases began to unravel.

How often does an innocent person get convicted? Twenty Florida inmates have been exonerated from death sentences after their cases were reexamined. DNA has cleared more than 90 prisoners held for a variety of offenses nationwide. While these are a fraction of America's inmates (Florida prisons hold 73,000), only a few old cases are ever reexamined and fewer have evidence with DNA.

Although justice is an honorable ideal, America's criminal courts and police agencies too often act as factories churning out a product. If they are not forced to study their failures, there will be more innocents behind bars