ANNAPOLIS — A push to abolish the death penalty in Maryland cleared a key hurdle Wednesday, when the Senate approved the measure that appears to have support in the House and the backing of Gov. Martin O’Malley.

Two Republicans — Sens. Edward Reilly of Anne Arundel County and Allan Kittleman of Howard County — joined 25 Democrats in supporting repeal on a 27-20 vote. Ten Democrats and 10 Republicans opposed the legislation.

Death penalty opponents argued that capital punishment is costly, prone to error, racially biased and a poor deterrent of crime, while supporters insisted it must be an option for criminals who commit the “worst of the worst” crimes.

If the bill is finally approved, opponents have expressed confidence that citizens will petition to get the issue on the ballot for voters to decide if they want their state to punish by execution.

Still, the vote marked a long-sought victory for O’Malley, who has worked to ban capital punishment since shortly after he became governor in 2007.

If passed, Maryland would become the 18th state to ban the death penalty. Connecticut did last year. Illinois, New Jersey, New Mexico and New York also have abolished it in recent years.

Senators backing the bill repeatedly told the story of Kirk Bloodsworth, a Maryland man who spent two years on death row in the rape and murder of a 9-year-old girl outside Baltimore and was later exonerated because of DNA evidence.

Opponents countered with the death of 11-year-old Sarah Foxwell, who was kidnapped, sexually assaulted and killed on the Eastern Shore in 2009.  

“I’m jealous of all of you who have these very firm beliefs on this because I don’t,” said state Sen. Robert Zirkin.

The Baltimore County Democrat was instrumental in passing the 2009 law that limited capital cases to those with biological or DNA evidence, a videotaped confession or a videotape linking the defendant to a homicide.

“I’m torn. I listen to these horrible stories, and if you put me in a room with the person who did this I would take them out myself. But on the other side, you listen to a Kirk Bloodsworth. It’s one story. The question is, could there be others?”

Opponents said the state needs capital punishment for the worst of crimes.

“When we live in a time of mass murders, Oklahoma City, the World Trade Center, Virginia Tech, Aurora, Colorado and Newtown, Connecticut to name a few, why would we remove the ultimate sanction for such crimes?” said state Sen. E.J. Pipken, an Upper Shore Republican.  

Nearly every senator explained his or her support or opposition to the measure.

“We are not God,” said state Sen. Delores Kelley, a Baltimore County Democrat. “We are not smart enough to implement the death penalty.”

The measure is expected to come before the House of Delegates next week.

Maryland has five men on death row, but the pending measure makes clear that the governor can commute their sentences to life in prison without possibility of parole.

The state’s last execution took place in 2005, during the administration of Republican Gov. Robert Ehrlich. He resumed executions after a moratorium had been in place pending a 2003 University of Maryland study, which found significant racial and geographic disparity in how the death penalty was carried out.

Capital punishment was put on hold after a December 2006 ruling by Maryland’s highest court that the state’s lethal injection protocols weren’t properly approved by a legislative committee. The committee has yet to sign off on protocols.

Not long after the court ruling, O’Malley expressed support for repeal legislation. It stalled in the state Senate in 2007.

In 2008, lawmakers created a commission to study capital punishment after repeal efforts failed again. The panel recommended repeal later that year, citing racial and jurisdictional disparities in how the death penalty is used.