Prosecutors in the criminal trial of Dewey & LeBoeuf’s three top executives found their groove for the first time Thursday in their questioning of a well-liked retired partner and former executive committee member.

The former partner, Jane Boisseau, testified that Dewey & LeBoeuf used her $621,000 in equity capital in 2010 to offset firm expenses in violation of the now-defunct firm’s partnership agreement, and also broke a written promise to repay a capital loan that the firm encouraged her to take.