(written from a Production point of view)
Melvin Caesar Belli, credited as Caesar Belli, (born 28 March 1957; age 57) played Steve O'Connel in TOS: "And the Children Shall Lead". He is the son of Melvin Belli, who played Gorgan in that episode. This appears to be his one and only acting credit.
Belli is now a personal injury attorney in San Francisco.