In season 1 McCall's husband is described as a motorcycle cop who was shot during a traffic stop of a stolen vehicle. In Season 3 episode dedicated to "closing" his death changes him to a homicide detective killed by a hired gun.
In this flash back episode Dee Dee's deceased husband, Det. Sgt. Steve McCall, is killed during a murder investigation. However, in the 1984 "Hunter" pilot episode Dee Dee tells Hunter that her husband was a motor cycle officer who was killed by teenagers during a traffic stop.
No accounting for how David knew to tell McCall where to go and when to be there when the killer went to the father's office building.