Rockville got its first female mayor yesterday, the mayor of Baltimore was reelected, and the first African American was elected to the Board of Commissioners in Maryland's Atlantic shore county as the state's voters decided municipal contests.

Two-term City Council member Rose G. Krasnow was elected without opposition to succeed James Coyle as mayor of Rockville. Krasnow is a member of the nonpartisan Team Rockville slate, and three of her four running mates also were elected. They are newcomer Robert J. Wright and incumbents Robert E. Dorsey and James T. Marrinan. Rounding out the five-member council is independent Glennan Harrison.

Baltimore Mayor Kurt L. Schmoke (D) easily won a third term, defeating Republican challenger Victor Clark. Schmoke had beaten back a strong challenge from within his own party in September's primary.

On Maryland's lower shore, voters made James Purnell the first African American to win a countywide office in Worcester County's 253-year history. His election to the Board of County Commissioners followed a bitter and prolonged voting-rights lawsuit that was appealed to the Supreme Court.

The suit, filed by the American Civil Liberties Union and others, prompted federal judges to order the county to begin electing commissioners from five single-member districts. The new procedure replaced an at-large system that blacks said diluted their vote and effectively excluded them from elected office.

Purnell, a former president of the Worcester County NAACP, defeated Floyd E. Bassett, an incumbent Republican commissioner and the board president,, 744 to 659. Bassett conceded defeat. The voting district has a 58 percent black majority.

The election also changed the makeup of the five-member board, which had been solidly Republican. At least four of the five Republicans will be replaced by Democrats.

College Park Mayor Joseph Page ran unopposed for reelection as the city's 9,300 registered voters decided by a narrow margin in a referendum not to raise their property taxes to create a city police department. The proposed increase, from 57 cents to $1.22 per $100 of assessed value, would have covered start-up costs and the estimated $2.6 million annual budget of a 30-member police department.

The city now supplements coverage by Prince George's County police with four contract officers. A task force concluded that College Park needed to have a force of its own to improve response times, provide better police services and enforce local laws.

But the police measure failed to get the required 60 percent majority needed for enactment. It received 2,814 votes -- 58.7 percent -- to 1,981 against.

City Council member Michael Smith said the measure was just too expensive. "We leave it up to the citizens now," he said. "If there is support for police at a reasonable price, I think the citizens will bring it to the council."

County police do not currently enforce College Park laws, and many residents said they were willing to pay more taxes to get relief from loud music, shouting and vandalism from students at the University of Maryland. Students and city residents in College Park have a long history of mutual distrust.

In College Park council elections, incumbents Maxine A. Gross, John E. Perry, Michael J. Jacobs, Michael B. Smith, Peter J. King and Joseph L. Nagro were reelected. They will be joined on the new council by Sherrill T. Murray and John F. Anders. James D. Schultz was defeated, finishing third in his district.

In Greenbelt, all five council incumbents, including Mayor Antoinette M. "Toni" Bram, won reelection. The others are Edward V.J. Putens, Rodney M. Roberts, Judith F. Davis and Thomas X. White. According to unofficial returns, Bram was once again the highest vote-getter with 1,542 votes. Davis was next with 1,456 votes.

Calvert County voters decided by a 2-to-1 ratio to have an elected school board, replacing the decades-old appointive process.

Complete but unofficial results showed a turnout of 20 percent of registered voters, with 4,235 voting for an elected board vs. 2,101 for an appointed board.

"It's a victory for the children and the taxpayers of the county," said Republican Del. Anthony J. O'Donnell, whose party backed an elected board. He pointed to the wide margin as evidence that Democrats as well as Republicans voted for the measure.

Gracie Rymer, a proponent of an appointed board, saw the turnout as a warning sign for forthcoming elections, saying special-interest groups could dominate low-turnout balloting.

"I just hope all the citizens will pay close attention to the school board elections in the fall," said Rymer, who served on a commission that examined the system. Staff writers Louis Aguilar and Todd Shields and special correspondent Mara Stanley contributed to this report. CAPTION: After winning his third term, Baltimore Mayor Kurt L. Schmoke smiles at his wife, Patricia, as Lt. Gov. Kathleen Kennedy Townsend, right, applauds. CAPTION: James Purnell, center, the first black elected as a Worcester County commissioner, celebrates with Honiss Cane, left, and Terry Saxon, a losing candidate.