Anne Arundel County executive John Leopold leaves his misconduct trial Monday in Annapolis. (Annys Shin/THE WASHINGTON POST)

Anne Arundel County Executive John Leopold resigned Friday, three days after being found guilty of misconduct in office.

In a letter dated Thursday but hand-delivered Friday and effective immediately, Leopold, 69, said stepping down after a political career that spanned more than 40 years in two states “is the most difficult decision I have ever made, but I know that it is the right one in the best interest of the citizens of Anne Arundel County.”

Leopold (R) was convicted Tuesday by Circuit Court Judge Dennis Sweeney after a trial that featured testimony about his sexual encounters and misuse of his security detail and scheduler to perform personal and political chores.

Sweeney described Leopold’s behavior as “outrageous” and said that he was “predatory and cruel” toward his scheduler, Patricia Medlin, who testified that she was ordered to drain his catheter bag after he had back surgery, even though he was physically able to do it himself. The prosecutor labeled Leopold’s behavior “catheter abuse.”

Leopold’s resignation removed a thorny dilemma for the Anne Arundel County Council, which was scheduled to vote Monday on whether to declare his position vacant, effectively firing him and laying the groundwork to hire a replacement. The county attorney, however, had warned that would be premature, since under state law, Leopold’s conviction does not take effect until sentencing, scheduled for March.

Council member Richard B. Ladd (R-District 5) said Leopold’s resignation makes the vote moot.

“We’re relieved and happy that things unfolded as they did today,” he said. “We all feel the same way.”

The resignation apparently will allow Leopold to collect his full annual pension of $8,017, officials said. There had been some discussion among council members about taking steps to reduce it, but Ladd said he did not know if that avenue will be pursued now.

According to Ladd, the council should publish an ad for a new county executive next week and hold public hearings about potential candidates in the latter half of February.

Chief Administrative Officer John Hammond was named acting county executive.

Leopold did not respond to phone messages requesting comment.

In his letter, Leopold said he was resigning “with great sadness and personal regret.”

“It was a compelling and humbling experience for me to sit through two weeks of the trial and listen intently to the words expressed by the Court,” he wrote. “I acknowledge the serious errors in judgment that I made and do not want these errors in judgment to further distract the County from its ability to move forward in a positive way.”

Leopold was convicted on two counts of misconduct for using his security detail for his personal and political benefit. According to testimony in the trial, Leopold directed them to put up campaign posters and to compile dossiers on critics and rivals.

He was acquitted on a more serious charge of misappropriating funds. He also was acquitted on a charge of using his protection detail to take him to sexual encounters with a county employee in the parking lot of a bowling alley and helping him keep the liaison a secret from his girlfriend.

Leopold represented the county in the House of Delegates for two decades before being elected county executive in 2006. He also was a state lawmaker in Hawaii and ran unsuccessfully there for governor.