File: Last month, Maryland Gov. Martin O'Malley signed into law a plan for electricity ratepayers to subsidize what could be among the nation's first offshore wind farms. (Photo by Aaron C. Davis/The Washington Post)

Maryland became the sixth state in as many years to abolish capital punishment when Gov. Martin O’Malley signed legislation Thursday repealing the death penalty.

The new law could face a challenge at the ballot box next year, however. A group that has led successful petition drives in the past said it would announce Friday whether it will move forward with an expected bid to put the issue to voters in November 2014.

The bill was the first to get the governor’s signature during a ceremony that included 265 other measures passed during the extraordinarily busy 90-day legislative session that ended last month.

O’Malley (D) also signed bills to combat cyberbullying, allow undocumented immigrants to get driver’s licenses, expand early voting, reform campaign-finance laws and put in place the federal health-care law in Maryland.

And he put his signature on a measure to legalize medical marijuana well into the ceremony, which lasted about two hours. The event at the State House in Annapolis attracted several high-profile visitors, including NAACP President Benjamin Jealous, who supported the repeal of the death penalty, and Ray Rice, a Baltimore Ravens running back who campaigned for the anti-cyberbullying bill.

O’Malley has lobbied lawmakers for seven years to pass legislation to end capital punishment, arguing that it is costly and an ineffective deterrent. Under the new law, death sentences will be replaced with life in prison without the possibility of parole.

In order to put the issue to voters, would have to collect 55,736 signatures by June 30. The same group was instrumental in petitioning three laws to Maryland’s ballot last year, including the legalization of same-sex marriage.

Del. Neil C. Parrott (R-Washington), chairman of the group, would not confirm its intentions Thursday. But he and Baltimore County State’s Attorney Scott Shellenberger (D), a death penalty supporter who was vocal during the legislative battle, plan to appear at an announcement being staged at Camden Yards in Baltimore.

Jane Henderson, executive director of Maryland Citizens Against State Executions, said she was surprised by the possibility of a petition drive, and she questioned whether the group will have the funding and organization to run a ballot measure campaign next year.

“I would think it would be a challenge for them,” she said.

The medical marijuana legislation signed by O’Malley limits distribution to academic medical centers, which will be required to monitor patients and publish their findings. Legislative analysts say it is unlikely the drug would be legally dispensed before 2016. It is also unclear how many institutions might choose to participate.

Another new law allows the state to issue second-class driver’s licenses to immigrants without proof of lawful status. Supporters say the legislation will help immigrants improve their lives and will make Maryland roads safer. Opponents say they fear it will lure more illegal immigrants to the state.

Early voting will be expanded from six days to eight days under another measure. In addition, the new law increases the number of early voting sites and allows same-day registration for the first time during early voting periods.

The legislation that makes cyberbullying a crime was introduced after the suicide last year of a 15-year-old Howard County girl. The girl’s family said she took her life after being harassed online.

Maryland has been leader in implementing the federal health-care law, and O’Malley signed a measure Thursday that facilitates the establishment of health exchanges and expands the state’s Medicaid program.

He also signed three bills intended to give more protection to patients. One measure requires firms and practitioners who make or distribute sterile compounded medications to obtain a permit from the Maryland Board of Pharmacy. The legislation was proposed after last fall’s fungal meningitis outbreak.

Another requires all health-care staffing agencies operating in Maryland to be licensed by the state health department; it was proposed after a health worker accused of exposing thousands of patients to hepatitis C repeatedly lied about his background to obtain credentials.

The third tasks the health department with overseeing cosmetic surgery centers after three patients contracted serious infections from liposuction procedures at a Baltimore County facility and one of them died.

Lena H. Sun contributed to this report.