Welll, I think you're joking, but Elias Koteas, who played Casey Jones, wasn't in any of the NYC cop shows as a regular.

Christopher Meloni, who does indeed look similar, was in l&w svu.

Now, Koteas has played a cop as a regular cast member, but in Chicago, not NYC.

Also, as a total tangent, it never ceases to amaze me how many of Meloni's Oz castmates ended up playing cops over the years. And it isn't like most of that cast didn't show up in svu here and there lol. I always joke that there was a prison break, and everyone just ran to NYC and became cops, except Beecher, who turned to murder.