CONCORD, N.H. — After months of emotional debate, New Hampshire’s Senate on Thursday voted to leave intact the state’s centuries-old death penalty. Lawmakers voted 12-12 to repeal the death penalty, and the tie means capital punishment stays on the books.

But the Senate then voted to table the repeal bill, leaving open the possibility that it may be resurrected for another vote before the session ends.

“It didn’t happen today. It could happen next week,” said Renny Cushing, the bill’s chief sponsor. Cushing is a Hampton Democrat whose father and brother-in-law were murdered.

“It was a tie vote not to kill the bill,” said Cushing, who stood alongside Manchester police Chief David Mara in the Senate gallery as the vote was taken. The two men represent opposite sides of the issue. The only man on death row in New Hampshire is Michael Addison, convicted of killing Manchester police Officer Michael Briggs in 2006.

Mara and other Manchester officers have been passionate in speaking against repeal, saying they were echoing the sentiments of Briggs’ widow and children.

Sen. Bob Odell, a Lempster Republican, said he had always supported the death penalty.

“But today, I’m going to vote for repeal,” he said, saying he wouldn’t know how he would explain an execution to his young grandchildren.

The House last month voted in favor of repeal 225-104 and Gov. Maggie Hassan said she would sign the measure into law as long as Addison’s death sentence remained intact. The bill is crafted to affect only those crimes that occur after Jan. 1, 2014.

It was the closest a death penalty repeal measure has come since 2000, when both houses passed it but it was vetoed by then-Gov. Jeanne Shaheen.

The state’s last execution was in 1939, when Howard Long was hanged for molesting and beating a 10-year-old boy to death.

“I thank the Legislature for their open, fair and compassionate consideration of this sensitive issue,” Hassan said after the vote. “I know that each senator listened to all viewpoints and made a difficult decision, and I appreciate the respect they showed for New Hampshire’s democratic process.”

Before the vote, a number of senators spoke of their respect for their colleagues and the difficult decision they faced, saying it was a vote of conscience. The debate was civil, the mood of the chamber somber.

Had repeal passed, New Hampshire would have become the seventh state in seven years to abolish capital punishment.

Richard Dieter, executive director of the Washington, D.C.-based Death Penalty Information Center, testified earlier this month that four states have recently repealed measures that left convicts on death row. In Illinois, the governor commuted death sentences to life in prison without possibility of parole. Three states that repealed the death penalty still have convicts on death row, including Connecticut, Maryland and New Mexico.

Several factors drove the latest repeal effort in New Hampshire, from the marked decline in death sentences and executions nationwide to the cost and perceived racial bias in the Addison case. (Addison is black and got the death penalty; a white defendant who faced the same punishment in a different homicide the same year got life in prison.) Executions have gone from an average of 300 a year in the late 1990s to 39 in 2013.

The voices of those who supported repeal outnumbered death penalty supporters by about 5-to-1 during a Senate Judiciary Committee hearing earlier this month and included the parents and children of murder victims. Some new faces supported repeal, including former Chief Justice John Broderick and former Attorney General Philip McLaughlin.

Representatives of four police agencies testified against repeal, calling the death penalty a “strategic tool” to deal with the worst of criminals.