David Willard is the main antagonist of episode Know It All of Law and Order SVU in season 18. He was portrayed by Chris Diamantopoulos.
Willard had a troubled relationship with his employed named Jennifer Knowles, since he too was often accused by Jennifer's sister of being a compulsive controller, had one day when they were anguing about the termination of the relationship when Willard, who was already angry with and then when Willard offends Jennifer, she slaps him, and Willard punches him by simply killing him, he fears being arrested he soon makes it seem like who did it was serial killer named Alex Ryan who soon after was arrested, but in his interrogation, Benson realizes that it was not that he did it. Soon after, they discover that the rope that was used in the last three scenes of the crime was different from the rope that Ryan had used in his crimes, doing the investigations going to Willard. Benson and Tutuola call Willard for an interrogation and Benson confronts him about the murder of Jennifer and the he hails the New York police and emulates Alex Ryan, after which Willard denies all this and says that he will speak to lawyer and leave. Then Willard hacker Colin Bennet, that he was only calmed by Tutuola and Rollins, already that he was willing to commit suicide.
Willard then blackmails prosecutor Rafael Barba stripping him Barb from the prosecution telling about Ashtonja Abreu a girl who is the daughter of Mariana who is woman who testified against rapist who killed two woman, then Mariana asks for a loan to Barba that he accepts, she eventually died, leaving behind a 10-year-old daughter. Then the members of the SVU go to Willard's company to find out some evidence that shows him that he killed Jennifer, plus they find nothing.
After that, SVU finds a camera that he himself had recorded that shows him killing Jennifer, Willard after that is arrested, and sentenced to prison for manslaughter.