Maryland becomes 18th U.S. state to abolish death penalty

Maryland on Thursday became the 18th U.S. state to repeal the death penalty after Gov. Martin O'Malley signed the legislation, leaving life without the possibility of parole for the most serious offenders.

"Evidence shows that the death penalty is not a deterrent, it cannot be administered without racial bias, and it costs three times as much as life in prison without parole," a press release by the governor's office said.

The legislation goes into effect Oct. 1.

The last execution took place in Maryland in 2005, according to the Associated Press. The new measure will not apply to five men on death row but the governor can commute their sentences to life without parole, it said.