With the stroke of a pen this afternoon, Gov. Pat Quinn ended the practice of capital punishment in Illinois, closing the book on a deeply flawed system that nearly executed people for crimes they did not commit. Since 1977, the state has executed 12 people and exonerated 20 more who were facing the ultimate punishment. The Prairie State is now one of 16 states to ban the death penalty.

Quinn, a supporter of capital punishment, did not come to this decision easily. Since the bill's passage in the General Assmbly's lame duck session in January, the governor heard from supporters of repeal -- like Lt. Gov. Sheila Simon, U.S. Sen. Dick Durbin, Archbishop Desmond Tutu, the attorney and writer Scott Turow, Sister Helen Prejean, Cardinal Francis George, and ex-death row inmates -- as well as those who opposed it. Crime victims' families, prosecutors, and Attorney General Lisa Madigan were in the latter camp.

In a statement signing, Quinn wrote, "Since our experience has shown that there is no way to design a perfect death penalty system, free from the numerous flaws that can lead to wrongful convictions or discriminatory treatment, I have concluded that the proper course of action is to abolish it. ... With our broken system, we cannot ensure justice is achieved in every case."

Quinn's decision is not just a moral one. Since 2000, the state has spent around $120 million from the Illinois Capital Litigation Trust Fund on just 20 capital cases. Under the repeal bill, unspent or unobligated dollars in that fund will be reallocated to the Illinois Criminal Justice Information Authority to pay for services for families of victims of homicide and for law enforcement training.

The ban takes effect July 1, and was coupled today with the commutation of the sentences of 15 inmates currently on death row. When New Jersey abolished the death penalty in 2007, then-Gov. John Corzine also commuted the sentence of the eight people in the Garden State facing capital punishment. Quinn said he came to his decision to commute the sentences with the same reasoning that led to his signing of the ban.

In an email to Progress Illinois, David Protess, director of the Innocence Project at Northwestern University, celebrated Quinn's decision. "It's a great day for justice. Never again will innocent people be sentenced to death in Illinois. The governor's decision is the culmination of more than a decade of hard work by volunteer lawyers, investigators, journalists and journalism students," he wrote. "The abolition law reflects the power of innocence. Illinois today rightly joins 15 other states and most of the civilized world in banning executions."

Protess added that he gave the news of Quinn's decision to Anthony Porter, a man who was 50 hours from his execution when he was exonerated thanks in large part to the reporting of Protess's students.

UPDATE (12:30 p.m.): In a statement, Jeremy Schroeder, executive director of the Illinois Coalition to Abolish the Death Penalty, said, "This wasn't an easy decision for lawmakers and the governor, but it was clearly the right decision. We gladly stand with Gov. Quinn, supportive lawmakers and others who know the death penalty is broken beyond repair. Now we no longer have to pretend. We can get serious about addressing the other problems in our criminal justice system and helping other states take this flawed system off their books as well."

UPDATE (12:53 p.m.): Chicago Mayor-elect Rahm Emanuel said he supports Quinn's decision to sign the bill, claiming, "It's the right thing to do." Mayor Richard Daley disagreed and suggested that more DNA testing be used in criminal matters.

UPDATE (1:35 p.m.): Quinn's full signing statement can be read here.

UPDATE (3:31 p.m.): Watch Quinn's comments below: