By all accounts, Joel J. Seidemann, the veteran litigator who closed the case against Brooke Astor’s son Anthony D. Marshall and lawyer Francis X. Morrissey, is pugnacious, unrelenting and highly effective.

And Mr. Seidemann’s take-no-prisoners advocacy finally paid off in what was one of the most high-profile cases of his 27-year career. Yesterday, on its 12th day of deliberations, the jury delivered guilty verdicts on 15 counts of a 17-count indictment.