HARTFORD, Conn. (AP) - Lawyers for state death row inmates have released a study that concludes minorities are disproportionately sentenced to die for their crimes in Connecticut, and decisions to seek the death penalty are often arbitrary.

The findings of the study, led by a Yale Law School professor, are disputed by the state, and become the latest chapter in a complicated legal battle that began 13 years ago. Seven of the state's nine death row inmates have been challenging their sentences, saying there is racial and geographic discrimination in the use of the death penalty.

The issue will be debated at an unusual state Superior Court hearing Thursday and Friday in the gymnasium at Northern Correctional Institution in Somers, with the seven inmates scheduled to take part. Judge Stanley T. Fuger Jr. is scheduled to hear arguments on the state's motion to dismiss the inmates' court cases.

Yale Law School professor John J. Donohue III, who oversaw the study, said one of the most surprising findings is that the death penalty is often not sought for crimes that are more violent and disturbing than ones where lethal injection is pursued.

``There was basically no rational system to explain who got the death penalty,'' Donohue said Tuesday. ``It really is about as random a process as you can possibly construct.''

Over the past year, researchers reviewed 207 murder cases dating back to the early 1970s that were eligible for death penalty prosecution. Donohue said 60 percent of the defendants were minorities and 40 percent were white, numbers that conflict with the percentages in the general population.

Among the other findings in Donohue's 128-page report:

_ Black defendants receive death sentences at three times the rate of white defendants in cases where the victims were white.

_ Killers of white victims are treated more severely than people who kill minorities, when it comes time to decide the charges.

_ Minorities who kill whites receive death sentences at higher rates than minorities who kill minorities.

Of the inmates on death row, four are black, three are white and two are Hispanic.

Senior Assistant State's Attorney John Massameno, who will argue the state's case this week, disputed the report's findings and the inmates' allegations.

``There probably is no category of prosecution in the state of Connecticut that is more carefully and circumspectly pursued than capital litigation,'' Massameno said. ``The notion that it's arbitrary and capricious ... will be overwhelmingly refuted, nor is it racially discriminatory.''

Massameno said the study that was just released by the inmates' lawyers was actually the second one they commissioned, and it's not clear what the first report concluded. It was never released.

Another recent study, in which Ohio State University examined death row cases in 16 states, found that blacks who kill whites are more likely than other killers to be sentenced to death, and more likely to be executed. That study also showed that blacks receiving death sentences for killing nonwhites are less likely to be put to death than other death row inmates.

The Connecticut inmates' legal arguments date back to 1994, when condemned killer Sedrick Cobb asked the state Supreme Court for a chance to study the state's administration of the death penalty. Cobb was sentenced to lethal injection for the killing of a 23-year-old woman in 1989.

Several other death row inmates also went to court with issues of race and fairness, leading the state Supreme Court in 2003 to consolidate all the cases into one habeas corpus proceeding, another avenue for appeals that allows inmates to challenge their incarceration.

This week's hearings are part of that proceeding.

The state's last execution was in 2005, when serial killer Michael Ross, who was white, was put to death by lethal injection. It was the first execution in New England in more than 45 years. Ross declined to be part of the habeas corpus challenge.