My first thought was Hallee Hirsh, who played a very young psychopath in “Killerz”. She was the one who convinced her older friend to help her murder a young boy. Eventually they determine that she is completely ruined and will never be anything but a killer. Totally creepy and dead-on performance. I was shocked a few years ago to discover that this was based on a real case which happened in the UK in the early 70’s, and that the girl apparently grew up to be a normal member of society.
I also loved Molly Price in “Misconceptions”. She played Amy, a woman who intentionally had her boyfriend kick her in the stomach to kill her unborn baby so that they could squeeze money out of a lawyer they targeted as the father. For years this was my favorite L&O episode, and I always called it the “Amy” episode. I only learned its real name while I was looking it up today.
A few days ago I saw Annette O’Toole in “Mega”. She and Michael McKean play a couple who run a self-actualization seminar which is just a huge scam, and she ends up running a con on her husband to get him to murder someone so that he’ll go to jail and she’ll have all the money. Another totally creepy performance, especially at the end when Abby and Jack realize that she’s gotten away with it.
I can’t believe no one has mentioned Larry Miller as comedy club owner Michael Dobson – so good when he killed his first wife (in “Coma”) that they brought him back to kill his second wife in “Encore”. What I loved most about his performance in “Coma” was that I really believed that he loved his wife and couldn’t possibly be guilty, so I was completely shocked when he turned out to be the killer.
Finally, Daniel Hugh Kelly has been great in all of his L&O appearances (he played the Robert Blake character, as well as the councilman that Logan punches which leads to him being sent to Staten Island), but that’s just because I love Daniel Hugh Kelly in anything.