Castle to ER (1994)
4 connections
Castle
Law & Order
Hudson University from L&O also appears as the home of various victims and crimes in Castle,
Homicide: Life On The Street
Law and Order and Homicide crossed over on four episodes
Chicago Hope
Chicago Hope's Jeffrey Geiger accepted an organ of a victim on Homicide
ER (1994)
A reporter on Chicago Hope talked to Dr. Austin about having been accepted into the space program and mentions an ER doctor from County was also accepted. In a separate episode of ER Dr. Greene was accepted in the space program.