Medical Investigation - Season 1 Episode 17 Half Life (II)
Overview: The NIH team teams up with the officers of the 55th Precinct in New York City to try to figure out what is the source of an outbreak of Marburg, a deadly disease with no known cure. They also try to locate patient zero, a murder suspect on the run, who is helping to spread the disease throughout New York City. The crossover starts on Third Watch S06E16 In the Family Way (I)