His father, Francis Elmer "Frank" Heacock, a writer and publicist for Warner Bros., was killed in an auto accident in North Hollywood, California, on April 5, 1940.

Coe attended the University of Southern California and was discovered by a talent scout during a trip with his fraternity to Palm Springs in the mid-1950s.

[citation needed] Coe's early film roles included appearances in House of Bamboo (1955), How to Be Very, Very Popular (1955), On the Threshold of Space (1956), and D-Day the Sixth of June (1956).

[1] Coe's first really notable role was playing the lustful Rodney Harrington in Peyton Place (1957), based on the best-selling Grace Metalious 1956 novel of the same name.

[1] In 1961, Coe and Brett Halsey played magazine writers Paul Templin and Ben Gregory, respectively, with Gary Lockwood as Eric Jason, on the ABC television network series Follow the Sun from September 17, 1961, through April 8, 1962.

[3] After Follow the Sun folded, Coe appeared in a supporting role in Fox's The 300 Spartans (1962)[4] then guest-starred in 1962 on the first episode of the fourth season of Bonanza.

Entertainment writer Hal Ericson reported that friction (i.e., job security) on the set caused Bonanza producers to stick with the three brothers.