A group of activists Wednesday were expected to call for the resignation of Maricopa County Sheriff Joe Arpaio and ask the U.S. Attorney's Office to place the Sheriff's Office into receivership.

County Supervisor Mary Rose Wilcox, a longtime critic of Arpaio's management and immigration policies, is expected to be joined by several dozen protesters at a news conference announcing the plan following the Board of Supervisors' regularly scheduled meeting at 9 a.m.

Receivership is a legal process by which an organization or agency is placed under the control of independent outside management to rectify ongoing organizational or financial problems.

Arpaio's critics cite the misspending of $99.5 million by his agency over eight years and a recent internal investigation that found mismanagement by his top commanders as reasons to seek the sheriff's ouster.

The activists will also "encourage" federal prosecutors to move forward with an abuse-of-power case against Arpaio, former County Attorney Andrew Thomas and others, and ask the U.S. Department of Justice to put the Sheriff's Office, the county's largest agency, into receivership.

However, receivership is an unusual legal step that is difficult and oftentimes consuming to accomplish, making the likelihood of such an action for Arpaio's office tenuous.

Arpaio declined to respond directly to the actions, but his representatives said he indicated he would continue to work with the board despite the actions by "a small group of activists."

A spokesman for the U.S. Attorney's Office declined comment.

Since December 2009, a federal grand jury has been meeting periodically to review information developed by the Department of Justice during its probe of county law enforcement. That investigation is ongoing.

"We're asking for the resignation of Arpaio, and we will be pressing the federal government to . . . move the Sheriff's Office to receivership," Wilcox said. "The management of the finances of MCSO (Maricopa County Sheriff's Office) has been horrendous, and the recent report from Pinal County shows there's been abuse of power."

Randy Parraz, co-founder of Maricopa Citizens for Safety and Accountability, said members of that activist organization would attend Wednesday's Board of Supervisors meeting to press the five-member board to strengthen accountability for Sheriff's Office's finances.

Parraz and other activists have asked County Supervisor Andy Kunasek to set a public hearing and invite Arpaio to explain how his agency misspent nearly $100 million in money earmarked for jail operations. Kunasek has said he would not set a hearing because "I don't think it would accomplish anything." Kunasek and his staff have said the misspending has been discussed in prior meetings.

Parraz argued that Kunasek and the Board of Supervisors are failing to hold Arpaio accountable.

"All of the recent revelations about the Sheriff's Office have gone from bad to worse," Parraz said. "This is about Arpaio being accountable - not about (former Chief Deputy) David Hendershott taking the fall. Arpaio keeps saying he's in charge. But now, when we've got $100 million of misspending in funds . . . he's acting like he doesn't know what's going on. Arpaio claims not to know. If he didn't know, he's incompetent, and he needs to go."

It is rare for law-enforcement agencies to be placed in receivership, typically a process reserved for agencies that have committed some civil violation.

A Justice Department spokeswoman confirmed that a federal civil-rights probe into Arpaio's agency is ongoing.

However, it can take years of sustained legal troubles for receivership to take place. For example, civil-rights activists in Oakland are considering asking for receivership of the Oakland Police Department but only after years of trying to get the agency to adhere to a federal court order.

James Chanin, a Bay Area defense attorney working on that case, said receivership for law-enforcement agencies typically arises after a lengthy court battle, as it did in Oakland. After nearly a decade of lawsuits, negotiations and failed agreements, Chanin said a request for receivership was a possibility.

"We don't want that. That's our last choice," said Chanin, an Oakland resident. "I don't think it'd be good for the city. I don't think it would be good for the police department."

Last month, the county Office of Management and Budget said sheriff's officials misappropriated $99.5 million in restricted jail funds over the past eight years - $84.7 million from the sheriff's detention fund and $14.8 million in inmate-services money. Sheriff's officials have acknowledged that the money was misspent. They said that as employees were transferred around the agency, payroll records were not always updated, thereby creating budgetary problems that will have to be corrected.

Meanwhile, a six-month internal investigation into three of Arpaio's top commanders uncovered years of deceit, intimidation and other misconduct. Those findings led to the resignations of Hendershott and Deputy Chief Larry Black. The findings also led investigators to recommend the termination of a third sheriff's commander, Joel Fox.