Under Gov. George W. Bush, Texas has executed dozens of Death Row inmates whose cases were compromised by unreliable evidence, disbarred or suspended defense attorneys, meager defense efforts during sentencing and dubious psychiatric testimony, a Chicago Tribune investigation has found.

While campaigning for president, Bush has expressed confidence in the fairness and accuracy of the death penalty system in Texas, the nation's busiest executioner. He has said he sees no reason for Texas to follow Illinois' lead by declaring a moratorium on executions.

But an investigation of all 131 executions during Bush's tenure found that the problems plaguing Illinois are equally pronounced in Texas and that additional flaws undermine the state's administration of society's ultimate punishment.

While Texas' death penalty system has come under increasing scrutiny since Bush announced his candidacy, the Tribune investigation is the first comprehensive examination of every execution during his administration. The Tribune examined trial transcripts, legal briefs, appellate rulings and lawyer disciplinary records, and it interviewed dozens of witnesses, lawyers and judges.

The investigation found that:

With their client's life at stake, defense attorneys in 40 cases presented no evidence whatsoever or only one witness during the trial's sentencing phase.

In at least 29 cases, the prosecution presented damaging testimony from a psychiatrist who, based upon a hypothetical question describing the defendant's past, predicted the defendant would commit future violence.

In most of these cases, the psychiatrist offered this opinion without ever examining the defendant. Although this kind of testimony is sometimes used in other states, the American Psychiatric Association has condemned it as unethical and untrustworthy.

While capital cases make the greatest demands on defense attorneys, the lawyers in these cases do not always represent the legal community's best.

In 43 cases, or one-third, a defendant was represented at trial or on initial appeal by an attorney who had been or was later disbarred, suspended or otherwise sanctioned. Though most were punished after they handled these cases, their disciplinary records raise questions about their suitability for such a complex job.

In at least 23 cases, the prosecution's evidence at trial or sentencing included a jailhouse informant form of testimony so unreliable that some states warn jurors to view it with skepticism.

The prevalent use of jailhouse informants in capital cases was one of the central problems Gov. George Ryan cited when he declared the moratorium in Illinois.

In at least 23 cases, the prosecution presented a visual comparison of hairs, a kind of evidence so inexact that it is restricted or barred in some jurisdictions.

In many of these 131 cases, justice has been shaped by witnesses, experts and lawyers of questionable merit.

They include a forensic scientist who was temporarily released from a psychiatric ward to provide incriminating testimony in a capital case; a pathologist who has admitted faking autopsies; a psychiatrist, nicknamed "Dr. Death," who was expelled from the American Psychiatric Association; a judge on the state's highest criminal court who has been reprimanded for lying about his background; and a defense attorney infamous for sleeping during trials.

Yet all 131 of these cases cleared every hurdle designed to prevent flawed cases from proceeding to execution from the trial court through appeals to the governor.

Since reinstating the death penalty in 1976, Texas has executed 218 men and women, far more than any other state and about a third of the country's total. Many of the condemned were clearly guilty and even admitted their crimes, apologizing in final statements shortly before they were executed.

At the same time, seven condemned inmates have been exonerated in Texas, and questions of innocence linger in some cases where inmates have been executed or still sit on Death Row.

As governor, Bush has the final say on whether a death sentence is carried out, even though most cases were tried long before he took office in 1995. By his own account, Bush is loath to second-guess jury verdicts, and he almost always defers to reviewing courts to settle whether the trial was fair.