Maryland, which has not executed any one since 2005, is set to abolish the death penalty for good within days, becoming the 18th US state to do so.

A bill proposed by Governor Martin O'Malley to end capital punishment passed the state senate Wednesday, and the measure is widely tipped to also clear the house of representatives, where Democrats, who favor the bill, have a large majority.

Maryland has had capital punishment in place since 1638, when it was still a British colony. Today, just five inmates remain on death row in the state that borders the US capital, and their executions seem unlikely to take place.

"Let's fight crime with strategies that work and end this expensive, ineffective and unfair practice," O'Malley said on Twitter, minutes after the vote.

For Kirk Bloodsworth of the anti-death penalty Witness to Innocence group, the Maryland repeal is a major win.

"Words can not describe my emotion right now. Fighting the death penalty has been really important to us, and this state in particular is obviously a very special one for me," he said.

In 1984, at just 23 years old, Bloodsworth became "the most hated man in Maryland," accused of the rape and brutal murder of a nine-year-old girl. He was sentenced to death.

But nearly a decade later, DNA evidence proved his innocence -- the first ever case of DNA exoneration in the US.

"I spent nine years in prison with some of the five death row inmates. I cannot imagine how they're feeling at the moment, but we've been waiting for this for so long," Bloodsworth said.

Their fate is in the hands of O'Malley, who said he would decide each of the cases "as they ripen."

Emma Weisfeld-Adams of Equal Justice USA explained that the new law would not be retroactive.

"It would only eliminate the death penalty as a sentencing option going forward," she said.

However, Death Penalty Information Center executive director Richard Dieter said he expected O'Malley to rule against executing the remaining prisoners.

"Since he is the one pushing the repeal, he is very likely to commute their sentences to life imprisonment without the possibility of parole," Dieter said.

There is a precedent: Illinois's Democratic governor, Pat Quinn, did just that for his state's 15 remaining death row inmates as he signed a repeal into law.

For Weisfeld-Adams, Maryland's impending repeal comes as part of "a much broader national momentum away from the death penalty" in the US.

"It would be the sixth state in six years to end the death penalty. In total, 16 states have considered bills to repeal the death penalty in 2011 and 2012," she said.