Prince George’s County Council member Leslie Johnson, who made international news when she hid cash bribes in her bra, pleaded guilty Thursday to destroying evidence, but she plans to stay in office until she is sentenced in October.

County Executive Rushern L. Baker III (D) and other politicians called for Johnson’s immediate resignation, although state law allows her to keep her council seat until a judge imposes her sentence.

Johnson’s guilty plea comes six weeks after her husband, former county executive Jack B. Johnson (D), was convicted of accepting more than $400,000 in bribes from developers during two terms as the county’s top official. Leslie Johnson (D-Mitchellville) admitted in court that she tried to cover up those bribes by flushing a $100,000 check down the toilet and stuffing $79,600 in her underwear as federal agents knocked at her door.

The Johnsons’ convictions, after a six-year federal corruption investigation, mark the fall of an ambitious power couple who were known as public faces of African American success in Prince George’s.

“The evidence shows that Jack Johnson and Leslie Johnson are guilty of a disgraceful abuse of the trust placed in them by the citizens of Prince George’s County,” U.S. Attorney Rod J. Rosenstein said Thursday.

Leslie Johnson, a lawyer and former administrative law judge in the District, briefly addressed reporters as she left U.S. District Court in Greenbelt but would not take questions. Her husband didn’t accompany her, but she was flanked by two lawyers and her minister.

“There is nothing I can do or say that would make this day any less difficult,” Johnson said, reading prepared remarks. “I made a mistake.” But she asked to be defined by the “countless days, months and years” she has spent helping county residents.

“I look forward to continuing to serve and help the lives of those in need,” Johnson said.

Her attorney, Shawn M. Wright, later said that Johnson intends to stay in her council seat, a position that pays $96,417, until her sentencing hearing Oct. 13. Prosecutors said they would seek a jail sentence of 12 to 18 months.

Under Maryland law, elected officials convicted of felonies must step down. But a conviction is not considered final until sentencing, which would give Johnson 31 / 2 more months in office and about $28,000 in before-tax income, as well as the opportunity to vote on key issues.

The amount of time between the conviction and sentencing hearing in Johnson’s case is typical in federal court cases, allowing time for both sides to prepare.

Several people have said they would seek Johnson’s seat in a special election.

Baker said he spoke by phone with Johnson on Thursday and asked her to step aside. He said she was composed but noncommittal about her plans.

“It is in the best interest of the county and of the residents of District 6,” Baker said. “We know there is going to be a special election. It is going to happen. It would be better for the residents of District 6 to get on with the process.”

Three of Johnson’s colleagues on the nine-member council also said she should resign.

William A. Campos (D-Hyattsville), who formerly worked for Jack Johnson, was among the first county politicians to publicly call for her resignation.

“My personal opinion is that she should step down for the benefit of the council, and for her benefit,” Campos said. “It doesn’t make sense to wait any longer. Whoever comes in to replace her, we have to get them up and running.”

Mel Franklin (D-Upper Marlboro) said that he has “tremendous affinity” for Johnson but that she should “resign rather than prolong the inevitable outcome to this tragic situation.” And Eric Olson (D-College Park), who last year called for Johnson not to take office, also said she should step down.

Baker’s spokesman said the county attorney’s office said it would be difficult for the council to oust Johnson before Oct. 13. The county charter allows members to be voted out for physical or mental disabilities, but it does not address situations in which a council member admits a crime.

Leslie Johnson is the 12th person and the first sitting elected official convicted in the corruption probe that has roiled and embarrassed Prince George’s, which is struggling to remake its image, reduce crime and improve its public schools.

During the investigation of a pay-to-play culture and cronyism in Prince George’s, court papers show, FBI agents listened in on wiretaps, worked with informants, and searched county offices, businesses and private homes. The probe also revealed a scheme to distribute black-market cigarettes and alcohol.

The county’s former housing director, three developers and two police officers have also admitted guilt. Rosenstein said that the investigation is continuing and that “there are others who’ve been implicated.”

Jack and Leslie Johnson were well known in the Prince George’s community and beyond.

In June 1992, they appeared on the cover of the New York Times magazine for an article touting the county as a mecca for educated black professionals. Jack Johnson served two terms as state’s attorney and two as county executive.

Leslie Johnson, her husband’s longtime political confidante, seemed poised to begin a promising political career after she defeated a handful of opponents in the September Democratic primary with more than 40 percent of the vote. She ran unopposed in the general election Nov. 2. Ten days later, the Johnsons were arrested by FBI agents.

After she was arrested, Leslie Johnson’s council colleagues privately marveled about her ability to show no public anxiety about her court case. The council barred her from serving on committees. But she has been an active member, asking questions of council witnesses on topics ranging from health care to stormwater management, and she has engaged in proceedings and deliberations.

On Wednesday night, her council office sent out an invitation to a July 23 “business card exchange” for residents to meet with county officials who handle small-business issues and minority contracting.

Staff writers Aaron Davis, Hamil R. Harris and June Q. Wu contributed to this report.