Law & Order SVU Season 10 episode 18

In the 18th episode of the 10th season of Law & Order SVU, a serial killer brings a detective from another unit with an ego demanding he be the only one investigating. They discover that the killer killed 6 women, but only raped 4 of them. They discover he only goes for natural women, and he is escalating. They discover that he works for the airline and returns lost luggage. At first he throws them off by making them believe one of the murders took place a day earlier, a day he spent with his mother. But they see through his ruse and catch him in the act. 

Guest star Stephanie March reprised her role of ADA Alexandra Cabot

Guest star: Jeri Ryan 

Law & Order: SVU