Maryland has a large Catholic population, and the church opposes the death penalty.
In 2008, lawmakers created a commission to study capital punishment after repeal efforts failed again. The panel recommended a ban later that year, citing racial and jurisdictional disparities in how the death penalty is applied.
In 2009, lawmakers tightened the law to reduce the chances of an innocent person being sent to death row by restricting capital punishment to murder cases with biological evidence such as DNA, videotaped evidence of a murder or a videotaped confession.
According to the Maryland Department of Public Safety & Correctional Services website, Maryland has executed only five inmates since 1976. There were three in the 1990s, and two when Ehrlich was governor.
In contrast, neighboring Virginia has executed 110 inmates since the U.S. Supreme Court restored capital punishment in 1976, according to the Death Penalty Information Center. However, Virginia's death row population has dwindled to eight from a peak of 57 in 1995, in part because fewer death sentences are being handed down in the state amid an increased acceptance of life without parole as a reasonable alternative.
The center said death sentences have declined by 75 percent and executions by 60 percent nationally since the 1990s.
Connecticut abolished the death penalty last year. Illinois, New Jersey, New Mexico and New York also have outlawed it in recent years.