Florence Halop (Wilma Kestner) would act in another show by Barney Miller writer Reinhold Weege called Night Court (1984), where she played the bailiff Florence Kleiner, which would turn out to be her final performance.
As Wojciehowicz locks Wilma and Estelle in the cell, he refers to them as the Cherry Sisters. The Cherry sisters were a Vaudeville act of five sisters active from around 1890-1903 and were considered one of the worst acts in Vaudeville. When they sued over a negative review, the Supreme Court ruled against them (Cherry vs. Des Moines Register) and upheld the press's right to fair comment.
One of the classes offered by Thorndyke refers to Robert Vesco. In 1973, when security charges were being leveled against Vesco for embezzlement, he fled the US for Costa Rica, which passed a law preventing him from being extradited to the US.