Career
Coombs spent twelve years on active duty service with the United States Army Judge Advocate General"s Corps. During this time, he was an acting chief of military justice, senior capital defense counsel, and judicial advisor for the Iraqi Central Criminal Court, and was certified as a military judge. He was professor of law at The Judge Advocate General"s Legal Center and School (TJAGLCS) in Charlottesville, Virginia during 2006–2009, and in 2007 he was a co-supervisor in the University of Virginia Law Extramural (Moot Court) Advocacy Team.
Since his promotion to lieutenant colonel, he continues to teach trial advocacy and criminal law at TJAGLCS as a reserve officer
Coombs is also an adjunct law professor of trial advocacy at the Roger Williams University School of Law in Bristol, Rhode Island. From 2003 to 2005, he served as one of four defense counsel in the United States v.
Sergeant Hasan Akbar case, a matter which received wide coverage. Since 2010, he has been representing Chelsea Manning, previously known as United States Army Private First Class Bradley Manning, who was charged and convicted of improper release of classified information to Wikileaks.