Image caption Judge Gregory Weeks presides over the hearing in North Carolina's Cumberland County

In North Carolina, the Racial Justice Act seeks to remedy years of inequity on death row. But can racism be regulated?

In 1991, 18-year-old Marcus Reymond Robinson and a friend convinced Erik Tornblom, 17, to give them a ride home from a gas station.

Robinson and his friend then pulled a gun on Tornblom, forced him to drive to a field, took his car and his money and shot him in the head.

A jury later convicted Robinson, who is black, of pulling the trigger on Tornblom, who was white. The prosecution presented evidence that Robinson said he wanted to kill a "whitey".

He was sentenced to death and scheduled to be executed in 2007. But like many death row convicts, he has survived past that date, and continues to appeal his sentence.

Last week, he appeared in a North Carolina courtroom as the first death row inmate to present evidence under North Carolina's Racial Justice Act (RJA), a controversial law designed to compensate for bias in the judicial system.

He and his legal team are hoping the new law will offer him relief in the form of life in prison without parole.

In the process, they're putting racism itself on trial.

'Wild disparities'

Critics of the death penalty have long argued that it is applied in an uneven and unjust fashion.

"Currently, only about 1% of the people who are accused of intentional murder are receiving the death penalty. There are wild disparities," says Malcolm Hunter, one of Robinson's lawyers and executive director of the Center for Death Penalty Litigation.

Image caption Marcus Robinson was found guilty of killing Erik Tornblom

"I could show you the summaries of 50 cases any year in North Carolina and say 'I want to pick out the two or three that get the death penalty', and you'd never be able to do it."

A series of studies over the past 30 years show that race is often a significant factor in who gets the death penalty: that black convicts are more likely to receive the death penalty than white ones, that white victims are more likely to result in a death sentence than black ones.

For Shirley Burns, the mother of Robinson, the idea of sentencing bias isn't just an academic exercise. Her other son, Curtis, was killed in 2006.

His killer wasn't eligible for the death penalty but could have served life in prison. Thanks to a plea bargain, he is currently serving a 22-year sentence.

"Punishment for a crime is not wrong, but the way that it is dealt to different people is wrong," says Ms Burns.

Though it is currently unconstitutional to seek the death penalty for racially biased reasons, defendants must prove intentional bigotry to make their case.

That's a difficult order, says Frank Baumgartner, a professor of political science at the University of North Carolina.

"You would have to get someone to say I did this on purpose, and I did this for the reason of racial bigotry," he says. "It's almost never done."

But by looking at several cases over time, broader patterns of systemic bias emerge.

Excerpts from Racial Justice Act The defendant has the burden of proving that race was a significant factor in decisions to seek or impose the sentence of death in the county, the prosecutorial district, the judicial division, or the State at the time the death sentence was sought or imposed. The State may offer evidence in rebuttal of the claims or evidence of the defendant, including statistical evidence. Full text of the bill

In the 1987 Supreme Court case McClesky v Kemp, justices weighed whether these statistical patterns could be used to prove bias in a death penalty appeal.

In a 5-4 decision, the justices decided against the use of this data, noting that the matter was one "best presented to the legislative bodies" who could choose to pass specific laws addressing this concern.

In 2009, the legislature in North Carolina did just that.

Data defence

The Racial Justice Act (RJA) allows death penalty prisoners to use statistical patterns of injustice, not just the facts of an individual case, to prove bias.

A similar but weaker law exists in Kentucky, and has yet to be put to use.

Under North Carolina's RJA, Defendants are eligible for a life sentence without parole if they can show that they were more likely to receive the death penalty because of their race or the race of their victims.

They can also, as in the case of Marcus Robinson, try to prove racial bias in how the state used their "peremptory challenges" during jury selection.

These challenges allow lawyers for both the prosecution and the defence to strike a certain amount of potential jurors without cause, as long as in doing so they adhere to federal laws against discrimination.

Barbara O'Brien, a law professor from Michigan State University, studied the role of race in peremptory jury strikes in North Carolina from 1990 to 2010.

Image caption Shirley Burns says her son's first trial was biased

At Robinson's RJA hearing, she testified that, on average, North Carolina prosecutors in death penalty cases excluded qualified black jurors at more than twice the rate of qualified non-black jurors.

For Marcus Robinson's jury pool, qualified blacks were rejected 3.5 times more.

"Being black does predict whether or not the state will strike the potential juror, even when controlling for these other variables," she said.

The final jury seated in Robinson's case had nine white members, two black, and one Native American. The rate of black members on the jury, 18%, was not much different to that of North Carolina's black population, about 21%.

But under the RJA, the final makeup of the jury is not at issue. Instead, it's what role the state played to get to that point.

"Absent of other things, naturally the prosecution will want less blacks, defence will want more. The question is whether we should allow the prosecution to bleach juries," says Mr Baumgartner.

"Should the state, on our behalf, engage in a racially discriminatory pattern of behaviour?"

Colour blind justice?

For the family of Erik Tornblom questions about systemic bias and judicial fairness seem far removed from the death of their son. He is not a statistic, they say, and neither is his killer.

Racial Justice Act timeline 1987 Supreme Court decision McCleskey v Kemp says that under current law statistics cannot be used to prove bias in individual cases

Supreme Court decision McCleskey v Kemp says that under current law statistics cannot be used to prove bias in individual cases 2006 Legal challenges temporarily halt executions in North Carolina

Legal challenges temporarily halt executions in North Carolina 2009 The North Carolina Senate passes the Racial Justice Act. Opponents include district attorneys and conservative lawmakers.

The North Carolina Senate passes the Racial Justice Act. Opponents include district attorneys and conservative lawmakers. 2011 Amid continued opposition to the RJA, the Senate passes a new version of the bill, which eliminates the use of statistics. It's later vetoed by the governor

Amid continued opposition to the RJA, the Senate passes a new version of the bill, which eliminates the use of statistics. It's later vetoed by the governor 2012 As of January, all but a handful of North Carolina's 158 death row inmates have filed a claim under the RJA

"What do people in Michigan have to do with us in North Carolina?" Patricia Tornblom, Erik's stepmother, asked after the first day in court. The family wore buttons that read "Justice is color blind".

To them, the only racial bias that matters should be the one that Robinson displayed when seeking out a white victim.

The prosecution cannot make this argument. They cannot provide details of the murder and argue that the death penalty was well deserved. They can only present their own statistics expert, as well as evidence from the judge and prosecutor in Robinson's original trial.

Both men maintain that race was not a factor in the state's jury selection process. More judges are expected to testify to similar effect.

But the Racial Justice Act fundamentally redefines the way the judicial system views racism. For years, the courts only saw racism as a deliberate act, done with malice.

The RJA says that racism has more to do with subtle shifts and built-in prejudices that permeate what should be a fair process.

"People can be motivated by race without even realising it," said defence attorney James Ferguson in his opening arguments. Later, he presented expert witnesses testifying to that same claim.

The hearing is expected to wrap up within the week, after which Judge Greg Weeks will make a ruling.

His decision as to whether or not Robinson qualifies for a new sentence will help shape the way that the law is interpreted in the future, and will reveal how far-reaching the consequences of the RJA could be for death row inmates, state prosecutors and the people of North Carolina.

Either way, his decision is expected to face appeals, and to serve as a historic moment in the ongoing debate over how American courts deal with race, justice and death.