PORTLAND — The sheriff of the most populous county in Oregon is about to become a police cadet again at the age of 70.

Multnomah County Sheriff Bob Skipper had asked for a waiver after returning to the job out of retirement. But the state agency that certifies police officers says he must go through the four-month basic training for new recruits.

The state Department of Public Safety Standards and Training allows exceptions but decided Skipper’s 34 years in the sheriff’s office — including five as sheriff — didn’t outweigh the 13 years he had been away.

So next month, Skipper will head to the academy in Salem for 16 weeks to become what may be the oldest police cadet in state history. The average age of the last class was about 26.

Multnomah County Chairman Ted Wheeler and District Attorney Michael Schrunk have written letters appealing to the agency to reconsider.

They note that Skipper has trained in firearms, use of force and police law and passed fitness, shooting and driving tests.

But that has failed to sway the certification agency, and Skipper has taken his case to the media in hopes that a public outcry might change somebody’s mind.

“My job is not to write citations — I am the CEO,” Skipper told The Oregonian newspaper as his office prepares for a $9.4 million budget cut and large-scale layoffs.

“I’m having to back myself out of the middle of all this and say, ’I can’t deal with this right now. I have to go off and learn to be a patrolman.”’

Former Multnomah County Sheriff Dan Noelle supports Skipper, saying he needs to spend the entire remaining 18 months in his term cleaning up problems left by the previous sheriff, Bernie Giusto, including a department reputation tarnished by an ethics scandal and sick pay abuse by deputies.

“Former Sheriff (Bernie) Giusto did a lot of damage, so that agency needs somebody that’s solid and steady and there every day,” Noelle said, arguing that four months at the academy will create a leadership vacuum at a critical time.

Skipper argues the state agency should make an exception because the training is designed for new officers, not veterans with a long career in law enforcement.

He also argues that his job is an administrative position dealing with the budget, personnel and politics of a large county office that would never require him to ride on patrol or make arrests.

And he argues that sending a veteran to learn basic policing is a waste of taxpayer money. He will earn $45,000 in county salary at the academy and the state will pay $15,000 to retrain him.

But Eriks Gabliks, deputy director for the training agency, said the law is clear.

“Anyone out over five years has to go back to basics unless they remained current somehow in law enforcement,” Gabliks said. “He hasn’t had that training or experience for more than 12 years. I’m not aware of someone being out that long and coming back.”