In the original novel, Rankin is a man, and his first name is Lattimer.
Hanging on the wall outside Goring's studio is the painting known as "Day's Catch" from The Case of the Absent Artist (1962).
Stock footage is used again when Perry leaves his parked car by the curb and walks up the steps into the "Los Angeles County Courthouse 1958." This footage was first seen in The Case of the Playboy Pugilist (1962), and was used again in The Case of the Skeleton's Closet (1963). Perry's car is a 1962 Ford Galaxie 500 XL convertible (claimed), and his license plate reads "XCF 01_" (probably "XCF 015"). This footage will be seen again in future episodes.
On the wall in the studio is a painting of a Cupid from The Case of the the Crying Cupid.
There was a painting of "The Three Witches" from The Posthumous Painter, in the apartment of Goring Gilbert.