The former co-chair of Post & Schell PC’s tax controversy and data protection groups has made the move to Ballard Spahr LLP in Philadelphia, the firm announced Monday, bringing experience helping corporations and individuals defend against misconduct allegations.

Peter D. Hardy joins Ballard Spahr’s white collar defense and internal investigations group as a partner after a more than 20-year career that saw him transition from assistant U.S. attorney to well-known white collar defense attorney with a particular expertise in tax issues, according to the firm.