November 13, 2012 http://bostonglobe.com

The state’s only death-row inmate will have his day in court — all day — when the New Hampshire Supreme Court hears arguments pertaining to his sentence.

Michael Addison was sentenced to death for fatally shooting a 35-year-old Manchester police officer, Michael Briggs, in 2006, when Briggs tried to arrest him on robbery charges.

The justices in Addison’s case will be deliberating the death penalty for the first time in more than 50 years — deciding, among other things, whether Addison’s sentence is just or was a product of passion or prejudice.

The justices will hear arguments in the case beginning Wednesday morning, holding four blocks of hearings that are scheduled to end at 3 p.m.

Court observers say the daylong hearing on Addison’s conviction and death sentence is unprecedented. A typical hearing before the justices lasts half an hour.

If his sentence is upheld and carried out, Addison — now 32 — would be the first convict executed in New Hampshire since 1939.

Former chief justice John Broderick, now dean of the University of New Hampshire School of Law, said the court, on occasion, has granted more time for arguments.

‘‘But an entire day? I don’t know of another case where that’s happened,’’ Broderick said.

Attorneys for Addison have raised 22 issues, with everything from the constitutionality of the state’s death penalty statute to the political ambitions of Kelly Ayotte, a former attorney general and current US senator, in their appeal.

Addison’s lawyers want the court to vacate his death sentence and order a new sentencing hearing. They stress that jurors determined Addison shot Briggs to evade arrest, but rejected the state’s argument that he shot Briggs with the intention of killing him.

Before Addison’s case could reach this point, the state Supreme Court first had to fashion the method it would use in weighing the fairness of his death penalty.

Addison’s lawyers argued his case should be compared with all other death penalty cases in this state and others, to test whether racial bias or other factors influenced his sentence. Addison is black; Briggs was white.

The only other New Hampshire capital case in decades to reach the penalty phase was that of John Brooks, who was convicted of plotting and paying for the killing of a handyman he suspected of stealing from him. A jury spared him a death sentence in 2008 — the same year Addison was sentenced to die.

But the court ruled in October 2010 that it would compare his death sentence with cases ­nationwide in which a police officer was killed in the line of duty.

The court stressed, in its 41-page ruling, that comparison cases do not have to precisely mirror the details of Addison’s case.

‘‘Ultimately, no two capital murder defendants are alike,’’ the ruling states. ‘‘Perfect symmetry and uniform consistency are not possible under a statutory scheme that requires juries to make individualized sentencing decisions based upon the unique circumstances of a case, given the nature of the crime and the character and background of the defendant.’’