Illinois abolishes the death penalty
Illinois has become the 16th US state to abolish the death penalty, after the governor signed a bill making permanent a 10-year-old moratorium on executions.
Governor Pat Quinn signed the bill after spending two months consulting with victims' families, prosecutors, religious leaders and others.
Former Governor George Ryan ordered a moratorium in 2000 amid concerns innocent people could be executed.
Thirty-four states still have the death penalty.
In the state capital Springfield, Mr Quinn, a Democrat, said he had followed his conscience, the Chicago Tribune reported.
"Fellow citizens, we cannot escape history," he told reporters. "I think it's the right, just thing to abolish the death penalty."
In a statement accompanying the bill signing, he wrote the Illinois death penalty system was flawed and could lead to wrongful convictions.
Mr Quinn also commuted to life in prison the sentences of 15 death row inmates.
Mr Ryan's move in 2000 came after more than a dozen condemned inmates were freed from Illinois death row, some when journalists showed they had been wrongly convicted.
His successors, former Governor Rod Blagojevich and Mr Quinn, kept the moratorium in place.
The Illinois legislature approved the ban two months ago, and it takes effect on 1 July.
The number of annual executions in the US has declined dramatically since the peak of 98 in 1999, to 46 last year, according to the Death Penalty Information Center.
Since the US Supreme Court allowed capital punishment in 1976 after a brief national moratorium, Texas has executed the most offenders, with 466.