Sean Parnell.Lamb is a veteran in the US Marine Corps Reserve and an attorney. He later became a federal prosecutor in the Department of Justice's Pittsburgh office in Pennsylvania's Western District.
In 2017, Lamb was chosen as the Democratic nominee for a special election in the state's 18th Congressional District after Republican Rep. Tim Murphy resigned following an alleged extramarital affair. Lamb narrowly defeated Republican Rick Saccone by fewer than 500 votes. In 2018, after the state's congressional map was redrawn under a court order, Lamb chose to run in the 17th Congressional District, where he defeated Keith Rothfus., Lamb serves as the vice chair of the House Committee on Veterans Affairs and is on the House Committees on Science, Space, and Technology, and Transportation and Infrastructure. He's focused his time in Congress on veterans' issues and economic issues facing Western Pennsylvania, including bolstering the steel industry.