"I carried out 37 executions by lethal injection and 25 by electrocution," said Givens on Wednesday night.
Givens, along with fellow former executioner and warden Ron McAndrew, of Florida, were in Bakersfield as guest speakers advocating for the passage of Proposition 34 on California's November ballot.
Like Givens, McAndrew also carried out executions, but has since come to oppose the death penalty.
"I supported it through ignorance," said McAndrew.
The pair were invited to speak at Grace Episcopal Church, sponsored by California People of Faith Against the Death Penalty, an interfaith group.
Givens and McAndrew are touring the Central Valley, sharing their transformation from executioners to supporters of Prop 34, which abolishes the death penalty in California and replaces it with life in prison without the possibility of parole.
Givens said he came dangerously close one time to executing an innocent man. The inmate was eventually exonerated for his crime.
"If I carry out the execution, I have to carry the burden with me until I die that I took an innocent life," said Givens.
Kern County's top cops recently have come out against Prop 34 and in favor of the death penalty, saying executing a criminal gives closure to a victim's family.
"Nothing is more false!" said McAndrew.
Prop 34 has been struggling in the polls, but is gaining ground among the voters. According to the state's Legislative Analyst Office, California could save as much as $130 million a year if the death penalty is abolished.