MARTINEZ -- Two more prosecutors are suing District Attorney Mark Peterson over claims he retaliated against them for supporting his opponent in the 2010 election, bringing to three the number of federal lawsuits that accuse Contra Costa County's top prosecutor of punishing staff over politics since he took office nearly two years ago.

Peterson won the DA job in a November 2010 run-off after a contentious campaign season in which the majority of his colleagues supported local attorney and former judge Dan O'Malley.

"The lawsuits are without merit, and the allegations are an unfortunate product of residual feelings from the election," Peterson said, adding that he could not comment on specific claims. "I've worked very hard since the election to heal divisions within the office, including promoting many more of my opponent's supporters than those who supported me during the election."

Deputy district attorney Jill Henderson and former deputy district attorney Lucinda Simpson last week filed separate lawsuits alleging that Peterson retaliated against them because they were active in the O'Malley campaign. Their complaints follow a $6 million political retaliation lawsuit filed in April by prosecutor and former office administrator David Brown, who says he was demoted by Peterson and harassed by two of his managers in the election aftermath.

Contra Costa County, a defendant in all three suits, does not comment on pending litigation.

"Under Peterson, things have really gone off the rails at the DA's office," Henderson's attorney, Kathy Dickson, said. "It's been politicized more than it's ever been before, and morale is at an all-time low."

The plaintiffs and other current and former prosecutors will testify about political retaliation claims before an administrative law judge at a five-day county merit board hearing for Henderson that's scheduled to start Monday. The hearing comes as prosecutors and public defenders, the lowest-paid public attorneys in the Bay Area, deal with crushing case loads and are considering a strike over pay.

"In contrast to such retaliation, those who supported Peterson's candidacy have been rewarded with promotions and favorable assignments, in many cases despite the availability of far more experienced and accomplished prosecutors," Henderson's lawsuit says. "In many instances, such adverse actions led to early retirement or resignation by highly regarded, experienced, career prosecutors and have caused a substantial decline in morale within the District Attorney's Office."

Simpson served as a deputy DA for 11 years before she quit to take another job during the campaign season in August 2010. Her lawsuit seeking an undisclosed amount says that then-DA Robert Kochly approved her request to be placed on the office's rehire list, but Peterson removed her name once he took office.

Simpson alleges she was added back to the list and interviewed in December 2011 for an entry-level position, only to be passed over for a Peterson campaign supporter with less experience. Her suit includes county human resources director Ted Cwiek as a defendant. Her attorney could not be reached Wednesday.

Henderson is a 14-year deputy DA who claims she was transferred to an inferior position after the election and told by one of Peterson's managers that she "would not be moving up until she demonstrated her loyalty to Mark Peterson."

She alleges that she was also retaliated against for testifying against deputy DA Michael Gressett, a friend of Peterson and some of his managers, when he was accused of raping a junior colleague during a lunch break in 2008. Gressett has remained on paid leave since a judge dismissed his 13-count indictment and is suing the county, his former bosses, investigators and others involved in his criminal case for malicious prosecution.

Henderson's lawsuit further alleges that she and other women suffer ongoing gender discrimination that's pre-dated Peterson's reign. It claims that women make less money, are denied promotions in favor of less-experienced male colleagues and in some case were told their maternity leave was a factor in being passed over.

Henderson's lawsuit demands a promotion with back pay and money for emotional distress.

"She's not asking for millions of dollars here; she's standing up because it's just wrong," Dickson said.

Contact Malaika Fraley at 925-234-1684. Follow her at Twitter.com/malaikafraley.