The Wire to Without a Trace
3 connections
The Wire
Homicide: Life On The Street
On The Wire (episode "That's Got His Own") Junior Bunk from Homicide was mentioned as someone who had once put bad drug product on the market causing deaths.
Law & Order
Law and Order and Homicide crossed over on four episodes
Without a Trace
Multiple episodes feature Hudson University, the Alma Mater of multiple L&O characters