Groot had been appointed counsel in several Virginia capital cases, appointed as defense legal analyst in federal death penalty cases, and consulted in several hundred capital cases, including Lee Boyd Malvo (Beltway Sniper)[2] and Peter Odighizuwa (Appalachian School of Law shooting).
New York Times reporter Jayson Blair wrote an article about Groot's defense of Malvo.
[6] Groot authored many law review articles on criminal law/procedure topics, especially the early history of trial by jury.
Groot was a member of Phi Beta Kappa, Order of the Coif, a member of the Board of Governors of the Virginia Bar Association, and a Fellow of the Virginia Law Foundation.
He died while hunting at the age of 63 on November 12, 2005, of a cardiac arrhythmia caused by idiopathic dilated cardiomyopathy.