LOS ANGELES (AP) — Three former California governors joined prosecutors and families of murder victims Tuesday to urge voters to reject a ballot proposal next week that would abolish the state's death penalty.

Appearing at downtown Los Angeles hotel, Democrat Gray Davis and Republicans Pete Wilson and George Deukmejian warned that Proposition 34 would erase history, punish victims' relatives and potentially free imprisoned killers.

There are more than 700 inmates on California's death row, though no executions have occurred since 2006 because of pending lawsuits.

The proposal "is a horrible injustice. ... These people had their day in court," Davis said. "Do not let the bad guys on death row win."

Wilson called the proposition "a travesty ... re-opening heartbreak."

The American Civil Liberties Union and other supporters say $4 billion has been spent since 1978 to house death row inmates and on court appeals that grind on for years. They argue that the money could be used to investigate unsolved murder and rape cases.

If voters approve Proposition 34, inmates awaiting execution would have their sentences converted to life in prison without the chance of parole. In addition, $100 million in grants would be doled out to law enforcement agencies over the next four years to investigate cold cases.

But the governors disputed the savings estimates and argued that far more would be lost in suffering by victims' families if the courtroom sentences are set aside.

Also, opponents say those sentences could be commuted in the future, possibly freeing murderers once on death row.

"We've had enough crime victims in this state," Wilson said.

Gov. Jerry Brown, a Democrat with a history of opposing the death penalty, has not announced a position on the proposal.

Former NFL star Kermit Alexander, whose mother, sister and two nephews were murdered in a botched 1984 contract killing, struggled to keep his composure when recalling his family members. Prosecutors said the killers had been looking for another woman but went to the wrong house.

Alexander said he has forgiven triggerman Tiequon Cox, who was sentenced to death, but "it doesn't erase the consequences."

Thirteen executions have been carried out since the death penalty was reinstated in California 35 years ago. During that same period, 89 death row inmates have died of natural causes, suicide or murder.