Just asking: If I can’t get chosen for jury duty in a no-drama lawsuit, how come a serial killer manages to be seated in a double murder case? According to Steve Cavanagh’s wickedly clever courtroom drama, THIRTEEN (Flatiron, $26.99), what it takes is an ingenious mind and a supreme feat of engineering. That plus the gall to murder any potential jurors who stand in your way.

Joshua Kane is one of those monsters whose wicked brilliance makes them unforgettable. After targeting a prospective juror who meets his needs, Kane executes a masterful maneuver to kill this innocent nobody, steal his jury summons and impersonate him at what’s being called “the murder trial of the century.” Why Kane would want to adjudicate the fate of Robert Solomon, a movie star accused of murdering his wife and his bodyguard, is an open question at this point. But the young actor’s defense team includes Eddie Flynn, an attorney who picked up some neat tricks in his 10 years as a con artist, so there’s hope for the poor guy.

Although the real fun happens in the courtroom, Cavanagh has actually written a two-for-one, a courtroom drama that’s also a serial killer mystery. These genres don’t exactly complement each other, but they don’t bump heads either.

To be sure, the serial killer gets all the best scenes and much of the choicest language. (What we would call coldblooded murders, Kane describes as making certain “mortal adjustments to the jury pool to increase his chances.”) The novel’s accounts of these killings, it should be noted, are extremely graphic, especially since Kane keeps up a running commentary as he goes about his work. “The side of the skull is not as well protected as the frontal cranium,” we learn in one of a series of monologues we could live without but are shamefully willing to share.