A new headquarters for the Frederick Police Department is expected to cost more to build than originally anticipated. The city’s alderman and staff are exploring the best way to secure extra money. Costs for the city’s new police headquarters are expected to be about $4.7 million more than the $19.81 million originally projected, because of changes in building costs and other factors, the city’s director of strategic planning and executive projects, Marc DeOcampo, told the city’s aldermen at a meeting Wednesday afternoon.