Freeing convicted cop-killer Timothy Brown from prison may prove easier than putting another man behind bars for the crime, legal experts said Wednesday.

Attorneys for Brown -- serving a life term for the 1990 murder of Broward Sheriff's Deputy Patrick Behan -- hope to persuade a federal judge they have new evidence that would have raised a reasonable doubt in the minds of the jurors who convicted him.

That evidence is the statements of Andrew Hughray Johnson, who, according to newly released investigative files, told his wife and several undercover agents he had killed a deputy and gave details that matched the Behan slaying.

Johnson emerged as the subject of a reopened Behan investigation last April. Word leaked to Brown's attorneys and the public in February.

Sheriff Ken Jenne concluded after 10 months of investigation that he lacked the evidence to seek charges against Johnson, a former sheriff's jail guard.

But the evidence may be more than enough to help Brown.

The key, legal experts say, is whether a jury would have convicted Brown if it knew about Andrew Johnson.

'It's always a stronger argument when you can say, `Not only is it not my guy -- it's that guy over there,' '' said Robert Jarvis, a law professor at Nova Southeastern University.

Now, the question is whether someone -- a judge, a prosecutor, even the governor -- will decide that the case against Brown is suspect enough to warrant overturning his conviction.

TWO EXONERATED

Twice in the past two years, convicted murderers from Broward have been exonerated, their slates wiped clean. But both of those cases involved DNA testing, which provided scientific certainty that Jerry Frank Townsend and the late Frank Lee Smith were innocent.

Tim Brown's task is not so simple. A jury convicted him of murder based on questionable statements in a case with no scientific evidence. There is no DNA to test. Brown has appealed unsuccessfully for nine years.

''It's going to take the combination of either a forceful judge or an enlightened prosecutor to open up his cell door,'' said Steve Drizin, a Northwestern University law professor who specializes in false confession and knows the Behan case.

GLITCHES IN CASE

Brown says he was beaten and psychologically manipulated into a false confession. Lawyers point to several other red-flag issues: Brown was 14 at the time of the murder, borderline mentally impaired and easily led; his mother was barred from the interrogation room; little of Brown's statement matched the known facts of the murder. Much the same is true of Keith King, convicted as Brown's accomplice on the strength of a muddled confession.

King served nine years and was released in 1999.

The Fourth District Court of Appeal heard many of those arguments and nonetheless affirmed Brown's conviction in 1995.

Judge Barbara Pariente, now a Florida Supreme Court justice, made the lone dissent.

''I have serious doubts about the voluntariness of [Brown's] statement,'' she wrote, citing Brown's age, his 56 IQ and the ''coercive aspect'' of his interrogation.

However, the stacks of new evidence emerging from the Andrew Johnson investigation will add tremendous weight to Brown's appeal, experts say, because none of it was available at the time of his conviction.

Brown's attorneys will be able to compare his statements with those of Johnson, who gave undercover agents detailed descriptions of the murder.

''Brown's confession and King's confession describe a different crime than the crime that occurred, while Johnson's [statement] more closely describes the death of Behan,'' said Drizin, the Northwestern law scholar. ``So what you have is a diminishing case for the guilt of Brown and a strengthening case for the guilt of Johnson.''

DEFENSE'S ARGUMENT

Brown's federal public defenders, Brenda Bryn and Tim Day, contend the new material would have given Brown's original trial attorneys more than enough evidence to create reasonable doubt with the 1993 Broward jury that convicted him.

''There is no less than 10 times the evidence in this reopened investigation [of Andrew Johnson] than there ever was in the Tim Brown investigation,'' Day said. ``The only evidence against Tim Brown was a coerced confession, and it has proven to be false.''

CRUCIAL JUDGMENT

If U.S. District Judge Donald Graham agrees that the new evidence could have led a reasonable juror to acquit Brown at the original trial, that would open the door to a much broader set of hearings at which Bryn and Day could raise any number of challenges to the original conviction.

If the judge were to side with Brown at this second set of hearings and find his confession unconstitutional on any of those grounds, it could easily set him free.

Charles Morton, the Broward State Attorney's chief homicide prosecutor, did not present any scientific evidence or call any eyewitnesses who directly linked Brown to the murder at trial.

''The top issue is whether Tim Brown should be in prison,'' said Martin McClain, an attorney representing several Broward men on Death Row.

``And there's enough doubt that he shouldn't be.''

Staff writer Wanda J. DeMarzo contributed to this report.