Law & Order: Who Does Sam Waterston's Daughter Play In His 400th Episode?

When "Law & Order" returned in 2022 after its initial decade-long hibernation, fans had much to celebrate as it meant some of the franchise's most beloved characters would end up coming back. This, of course, included the welcome return of tenacious district attorney Jack McCoy, played by Sam Waterston. The actor's portrayal of McCoy has delivered some of the series' most powerful and arguably thought-provoking courtroom moments. It is difficult to imagine the latest seasons of "Law & Order" without Waterston, as he's served an incredibly long tenure with the hit procedural. In fact, with the upcoming Season 22 finale on May 18, 2023, Waterston will have hit the milestone of 400 episodes.

And for his 400th outing, "Law & Order" will be a total family affair. The Season 22 finale, "Open Wounds," will feature the veteran actor's daughter Elisabeth Waterston as McCoy's daughter Rebecca. And while Elisabeth's character follows in the family practice of lawyering just like dear old dad, the episode promo for "Open Wounds" teases that this isn't exactly going to be a laid-back reunion. Jack and Rebecca face off in the courtroom as Jack's daughter defends a teacher who murdered a senator. And Jack has to prosecute the defendant. It's the type of high-stakes conflict and drama "Law & Order" is known to deliver. But for Waterston, acting with his daughter brought him some of the most fun he's had on the series.

"Open Wounds" teases that the relationship between Jack and Rebecca McCoy is likely strained beyond the courtroom clash. And while speaking with TV Insider, Sam Waterston confirmed the personal tension on screen between the father-and-daughter lawyer duo. He added that some things between Jack and Rebecca McCoy hadn't been resolved as a family. So it appears we'll be seeing how their personal feelings play into their legal battle, which should make for an explosively dramatic "Law & Order" finale. And isn't that always the best way to end a season of the classic crime drama?

Fortunately, things were much more positive behind the scenes. While clearly a proud parent, Sam Waterston further expressed how much he enjoyed acting alongside his daughter. The "Law & Order" veteran told TV Insider, "She's a beautiful actress, quick to react, full of intelligence and ready emotion. I have three actor children, and there isn't anything more fun than acting with them." 

"Open Wounds" won't be Elisabeth Waterston's first time on the series. In 2000, she appeared in the Season 10 Episode, "High & Low," as the character Penny Rollins. It's unknown whether we'll see more of Elisabeth on "Law & Order" next season. But the prospect of seeing her appear as Rebecca again seems too good to pass up.