In 1963, Dexter was cast as California Supreme Court Justice David S. Terry in “A Gun Is Not a Gentleman” on the syndicated anthology series, Death Valley Days, hosted by Stanley Andrews. Carroll O’Connor portrayed U.S. Senator David C. Broderick of California, who mortally wounded Justice Terry in an 1859 duel. Though past allies in the Democratic Party, Terry, a slavery advocate, challenged the anti-slavery Broderick.

Dexter’s friendship with Frank Sinatra began when Dexter saved Sinatra from drowning on May 10, 1964, during production of the World War II film None but the Brave (1965) on the island of Kauai, Hawaii. Sinatra and Ruth Koch, the wife of producer Howard Koch, were swimming when they were swept out to sea by the outgoing tide and nearly drowned. Sinatra’s co-star Dexter and two surfers swam out and rescued them. Dexter was later awarded a Red Cross medal for his bravery. Grateful, Sinatra made him vice president of Sinatra Enterprises.

He was married to Star-Kist tuna heiress Mary Bogdanovich from January 27, 1971, until her death on June 12, 1994. Later in 1994, he married June Deyer and remained with her until his death.

Dexter died in Rancho Mirage, California, from emphysema, on December 11, 2002, at age 85, and is interred at Desert Memorial Park.