(written from a Production point of view)
Kowal also had small roles in three movies – Portrait of a Mobster in 1961 (with Ken Lynch), The Split in 1968 (with Barry Russo), and The Wrecking crew in 1969 (with Rex Holman) – and over a dozen television guest appearances from 1965 through 1972. Among the more notable shows he appeared on were Bewitched, Voyage to the Bottom of the Sea, The Fugitive, and an episode of I Spy with Ricardo Montalban, Roy Jenson, France Nuyen, and Kenneth Tobey. He was also seen in multiple episodes of the Western series Bonanza (featuring Charles Seel as a regular cast member), including one episode with Robert Lansing and a three-parter with John Crawford and Jonathan Lippe. Kowal also appeared with Jonathan Lippe in an episode of The Fugitive.
Kowal served as a 1st Lieutenant in the US Army during the Korean War.