SPRINGFIELD, Illinois (Reuters) - Illinois Gov. Pat Quinn said on Wednesday he would “reflect” on the death penalty ban passed by the state legislature before deciding whether to sign it.

Illinois Governor Pat Quinn speaks to the press after a meeting with President Barack Obama during a National Governors Association meeting at the White House in Washington, February 22, 2010. REUTERS/Larry Downing

“Anyone in Illinois who has an opinion, I’m happy to listen and reflect and I’ll follow my conscience,” Quinn told reporters. If he agrees to the ban, Illinois will be the first state since 2009 to abolish executions.

The Illinois Senate voted for the ban Tuesday afternoon. The House had approved it last week. Quinn said the opinion of the members of the legislature is “very serious indeed.”

Illinois has not executed anyone for more than a decade after former Republican Gov. George Ryan imposed a moratorium on the death penalty in January 2000. This followed a series of revelations that more than a dozen people had been sent to Death Row who were later found to be innocent.

Quinn, a Democrat, has said in the past that he approved of the death penalty for the most heinous crimes, but wanted to continue the moratorium.

Ryan took 167 prisoners off the state’s Death Row in 2003, and pardoned another 4. According to the Illinois Coalition Against the Death Penalty, 20 Illinois Death Row prisoners were found innocent. Reasons for release included prosecutorial errors, lying by witnesses and confessions by others.

Lawrence Marshall, a Stanford Law School professor who had represented several freed Illinois Death Row inmates, said the problem with trying to limit the death penalty to “heinous” crimes is that the emotion surrounding those crimes can lead to errors.

“It’s the very kind of passion that triggers the desire for the death penalty in a particular case that does have the potential to be blinding,” said Marshall, who co-founded the Center on Wrongful Convictions at Northwestern University.

Among Marshall’s clients was Rolando Cruz, who was on Death Row for years for the 1983 murder of 10-year-old Jeanine Nicarico, even though another man, Brian Dugan, admitted to the crime. After Cruz was freed, Dugan was convicted and is now on Death Row.

Opponents of lifting the ban include the Illinois State’s Attorneys Association, which has said the death penalty is needed for law enforcement and to achieve justice.

If Quinn signs the bill, Illinois would be the 16th state, plus the District of Columbia, to have no death penalty. New Mexico in 2009 was the last state to abolish the death penalty. There have been no executions in Illinois since 1999. The number of executions in the U.S. dropped 12 percent last year, according to the Death Penalty Information Center.

Other states where legislation has been introduced to ban the death penalty include Colorado and Kansas.