Dermody also worked as a legal advisor to Allegheny County's district justices, an instructor at the Community College of Allegheny County, and a faculty member of the Pennsylvania Bar Institute for Continuing Legal Education.[5]
In the general election, Dermody faced one-term Republican incumbent Ted V. Kondrich. The criminal justice system, education, and the environment were regarded as the top issues of the campaign.[10] Dermody ultimately defeated Kondrich, receiving 9,082 votes to Kondrich's 8,430.[11] He has been re-elected every two years since.
Dermody was chairman of the Subcommittee on Courts in the Judiciary Committee from 1991 to 2006, and served on the Pennsylvania Commission on Sentencing from 1991 to 2010, including 14 years as commission chairman.[5] In 1994, he was selected by House leaders to lead the investigation into charges against Supreme Court Justice Rolf Larsen, serving as a key House manager (prosecutor) in the impeachment trial that led to Larsen's eventual removal.[5][12]
He served as chairman of the Allegheny County's House Democratic delegation (1994–2006) and as caucus secretary (2006–2008).[4] In 2009, he was elected Majority Whip, the second-highest position for his party in the House. In late 2010, he was elected Democratic floor leader on November 17, 2010, after incumbent Todd Eachus was defeated in his bid for re-election.[13]
Dermody resides in Oakmont with his wife, Debra (née Hewetson) Dermody, who was his classmate in law school.[5] They have two children, Frank and Cara.