Veteran prosecutor Jackie Lacey led in early voting returns Tuesday in her bid to become Los Angeles County’s first African American and first female district attorney, with Deputy Dist. Atty. Alan Jackson and Los Angeles City Atty. Carmen Trutanich competing for a place in a November runoff.

Lacey’s strong showing was somewhat of a surprise in an election in which Trutanich was widely viewed as the favorite to become the county’s top prosecutor.

The early count included mail-in ballots turned in before election day and more than a third of precincts reporting from votes cast at the polls.

Trutanich, who faced intense criticism during the campaign, competed against five other candidates, all of them career prosecutors relatively unknown outside of the local criminal justice community.

In other Los Angeles County election contests, three county supervisors were cruising to victory.

Mark Ridley-Thomas, who is seeking his second term, and Don Knabe, who has served four terms, ran unopposed while Michael D. Antonovich faced opposition from a Palmdale businessman who raised little campaign money.

Voters also appeared to be favoring two county tax extensions that have been on the books since the early 1990s.

Measure H would keep a 12% tax on hotel stays in unincorporated parts of the county, and Measure L would maintain a 10% tax on landfill operators in unincorporated areas of the county.

Tuesday’s nonpartisan district attorney’s election was the first time in nearly 50 years that an incumbent was not involved in the race to run the most powerful office in the county’s criminal justice system — one responsible for prosecuting roughly 60,000 felony cases a year, including murders, rapes and robberies.

Three candidates — Bobby Grace, Lacey and Danette Meyers — hoped to make history in a county that has never elected a black district attorney, with two of them also aiming to become the first woman to hold the post.

The campaign was marked by unusual agreement on the need for crime-prevention programs and the rehabilitation of more nonviolent offenders to help keep the limited space behind bars for the most serious criminals.

But the candidates traded barbs over who would be best suited to lead the office.

Trutanich was considered an early front-runner, drawing on his position as the city’s top lawyer to raise about $1.5 million.

Trutanich, 60, said he would crack down on gang crime and advocate for after-school programs to keep children out of gangs, and for rehabilitation services for nonserious offenders.

He secured the support of Gov. Jerry Brown, Sheriff Lee Baca and the county’s Federation of Labor.

But he came under fire for several campaign missteps, including his about-face from a pledge he made during the 2009 city attorney’s election not to run for higher office until he finished two terms.

In April, a judge described his proposed ballot title, “Los Angeles chief prosecutor,” as “misleading” after Jackson took the issue to court.

Jackson, 46, is best known for his role in prosecuting legendary music producer Phil Spector for murder. He secured endorsements from the county’s Republican Party and more than a dozen local police unions.

He called for the repeal of the state’s prison realignment, which shifts responsibility for housing and supervising thousands of nonviolent prison inmates from the state to counties.

Lacey, 55, sought to make the jump from second-in-command in the office to the top spot held by Dist. Atty. Steve Cooley, who is retiring this year and endorsed her.

But she drew criticism for changing her testimony at two union grievance hearings and attributing the contradiction to being confused and having problems with her blood-sugar level.

Meyers, who handled the criminal case of actress Lindsey Lohan, was backed by the county’s Democratic Party, the union that represents the county’s line-level prosecutors, and former Dist. Atty. Gil Garcetti.

Running under the slogan “Smart Justice,” Meyers, 54, pledged to reduce the number of juveniles tried as adults and to partner with schools to slash dropout rates.

Grace, 51, called for more rehabilitation programs to reduce recidivism among low-level offenders and promised to work with schools and community programs to help, rather than punish, chronic truants by addressing why they are missing school.

John L. Breault III, 69, ran a relatively low-key campaign in which he promised to put more faith in line-level prosecutors rather than have supervisors second-guess decisions.

jack.leonard@latimes.com

Times staff writer Jason Song contributed to this report.