A subway station gas attack, similar to one that took place in a Baltimore church five years earlier, brings Baltimore detectives Tim Bayliss and Frank Pembleton to New York to assist Briscoe and Curtis.

This crossover continues on Homicide: Life on the Street S04E12 For God and Country (II).

It's old home week for Briscoe when an apparent murder of a teenage model in New York develops ties to Baltimore and Detectives Munch and Falsone pay a visit to the Big Apple to observe the case. Meanwhile, McCoy finds himself battling the attorney of the victim's parents for access to his clients and the Baltimore DA for jurisdiction.

This crossover continues on Homicide: Life on the Street S06E05 Baby, It's You (II).

When Briscoe and Curtis discover that a high-level federal official found murdered was recently transferred from Baltimore, they re-team with Baltimore homicide detectives. The joint investigation reveals that the victim was involved in an affair with a high-level government official whose career will be destroyed if it becomes public. The independent counsel summons McCoy and Ed Danvers to Washington to demand McCoy reveal his source or be jailed for contempt.

This crossover continues on Homicide: Life on the Street S07E15 Sideshow (II).

The focus of the case returns to a politically influential family and, during the course of the trial, McCoy finds the powerful matriarch to be a formidable opponent.

The crossover starts on Law & Order: Special Victims Unit S01E15 Entitled (I).