(CNN) -- The escape of three convicts from a prison in Arizona last week has become an issue in the state's campaign for governor.
Attorney General Terry Goddard, a Democratic candidate, is accusing incumbent Republican Gov. Jan Brewer of increasing the risk of jailbreaks by favoring for-profit prisons over state-run prisons.
"The Brewer administration has consistently promoted private over public prisons, in spite of the public safety risk," he said. "The escape of these two violent offenders makes it clear how dangerous this policy has been."
Goddard is calling for a moratorium on putting violent criminals in for-profit facilities. "They're going to cut costs wherever they can," he told CNN Tuesday, "putting public safety at risk."
Brewer's office says a review of security at private prisons is already under way and accuses Goddard of playing politics.
"His criticisms are little more than an irresponsible stunt attempting to score political points off of a terrible tragedy," said spokesman Paul Senseman.
The three inmates -- all convicted of murder, second-degree murder or attempted second-degree murder -- escaped July 30 from a for-profit prison in Kingman, Arizona. The prison is run by Management and Training Corp. of Utah. The facility was built to house minimum-security prisoners, but it was later modified to house medium-security inmates as well. Its current population includes 117 murderers classified as medium-security inmates.
Violent offenders, including murderers, can work their way down to medium-security or even minimum-security classification if they demonstrate good behavior over time, according to the Department of Corrections.
The attorney general accuses Brewer's administration of allowing inmates' threat levels to be too easily downgraded, so they can be housed in cheaper prisons. But the governor's spokesman said the classification system hasn't been changed since the previous Democratic administration and was properly followed in this case.
Goddard also alleged that "private prisons have a very, very strong influence" with Brewer, because spokesman Senseman was once a contract lobbyist for private prisons. But Senseman says that work was before he came to the Brewer administration and that it has no connection to the issue being debated.
He countered that it was a Democratic governor, Janet Napolitano, who approved both the original private contract for MTC's Kingman prison, as well as its expansion to house medium-security prisoners.
"I do not recall the attorney general requesting a special session call to reverse or void that decision," Senseman said.
State officials say the inmates escaped through a door at which the alarm failed to sound, then cut a hole in the fence with wire-cutters that had been thrown over the fence by an accomplice. They escaped undetected.
Arizona Department of Corrections Director Charles Ryan told CNN affiliate KPHO two days after the escape, "My concern is that the staff in the prison may have been lax in doing their job."
A spokesman for MTC declined to discuss the jailbreak, pending an investigation.
Arizona has 20 percent of its inmates in privately run facilities, and according to the Department of Corrections, the choice is saving the state money, such as the costs of building more facilities.
Private prisons can also have lower personnel costs such as salaries, benefits and pensions. They have more flexibility to hire and fire than state governments, said Arnett Gaston, a former chief of Rikers Island prison in New York who now teaches criminology at the University of Maryland.
"There is really nothing wrong with housing high-risk-security people in a medium-security facility," he said, "if the construction, the training and the technology meet the security needs." But because of the risk of an incident requiring the use of deadly force, "I would never use private agencies to guard violent prisoners."
MTC is the third-largest private prison operator in the country, with 17 facilities, according to the company's website. The company has pledged to cooperate with the investigation of the escape and put up $25,000 in reward money for information leading to the capture of the fugitives.
One of the three escapees, John McCluskey, remains at large.
CNN's Brian Todd contributed to this report.