Baltimore County’s Lisa Belcastro was sworn into office as a member of the Maryland House of Delegates Tuesday.Belcastro fills the final vacancy in the General Assembly caused by a cascading series of retirements, resignations and replacements.Belcastro, a Democrat, represents a district in the northwest part of the county. She replaces Shelly Hettleman, who was elevated from delegate to senator. Hettleman was appointed to the Senate seat made vacant by the resignation of Bobby Zirkin in January.Belcastro was recommended for the position by the Baltimore County Democratic Central Committee and appointed by Gov. Larry Hogan, a Republican. She is a physical education teacher for children with disabilities in Prince George’s County and an aide to Baltimore County Councilman Izzy Patoka, a Democrat.Belcastro was assigned to the Health and Government Operations Committee.