The painting they show being stolen is "The Concert" by Johannes Vermeer. This painting was subsequently stolen in real life from the Isabella Stewart Gardner Museum in Boston in 1990, and still has not been recovered to this day.
Police Lt. Wymar drives a 1964 Ford Custom 4-door. The Custom was a very popular model in "real world" police car fleets in the 1960s and 1970s.
At one point, Bellington repeats a quote, "Words are father to the deed." The original quote was from 19th century British philosopher Thomas Carlyle: "Thought is the parent of the deed."