Supporters of Maryland Gov. Martin O’Malley’s bill to repeal the death penalty turned back 18 proposed amendments Wednesday in the House of Delegates, including attempts to keep capital punishment on the books for cop killers, child abductors and terrorists.

The two-hour debate set the stage for a final vote Friday on the bill, which cleared the Senate last week. Passage by the House, which is expected, would send the measure to O’Malley (D) for his signature.

Following the Wednesday night House session, O’Malley told reporters he was encouraged by the proceedings, in which mostly Republican opponents of the repeal bill sought to gain leverage by relaying details of some gruesome murders.

“You can come up with a never-ending parade of horrible crimes ... but the fact remains that the death penalty is ineffective,” O’Malley said.

O’Malley’s bill would replace death sentences with life in prison without the possibility of parole in Maryland, where five prisoners sit on death row.

The first attempted amendment Wednesday sought to keep execution as an option for those who kill after already being sentenced to death or life in prison.

“Some people are vicious,” said Del. C.T. Wilson (D-Charles), the amendment sponsor. “They’re inhumane. They’ll do things we could never imagine, and they’ll do it again and again.”

Samuel I. Rosenberg (D-Baltimore), who shepherded O’Malley’s bill on the floor, argued that making any exceptions would not fix the underlying problems with the death penalty law, including the prospect of executing an innocent person.

“You can’t have a partial repeal,” Rosenberg said.

Wilson’s amendment failed 61-77, and no other proposed change garnered any more votes than that.

Other amendments sought to maintain capital punishment for killers of law-enforcement officers, fire fighters and abducted children. Other delegates proposed keeping the death penalty for those who kill on school grounds or who murder more than one person.

“What would happen if 30 innocent children were killed in our state?” Del. Patrick L. McDonough (R-Baltimore County) asked his colleagues as he argued for capital punishment for mass murderers. “Vote as a human being and a person on this issue.”

Del. Neil Parrott (R-Washington) floated three amendments in a row, all of which failed.

The first would have kept capital punishment for terrorists. The second would have kept capital punishment for terrorists who kill more than 100 people. The third would have kept capital punishment for people who kill more than 1,000 people.

Del. Patrick N. Hogan (R-Frederick) also unsuccessfully pushed an amendment that would have denied several privileges to inmates serving life sentences without the possibility of parole. Among them: access to television, the Internet, educational services and the library. The prisoners could also not have visitors.

“These are murderers and rapists,” Hogan said. “They do not deserve our compassion, and they certainly don’t deserve these privileges and amenities.”

Rosenberg argued that it should be up to prison officials to make such determinations.