Question: Which American actor was starred as Frank Cannon of "Cannon" on the first "Barnaby Jones" episode?

Context paragraphs:
Mark Shera: Mark Shera is an American actor, who is perhaps best known for his role as J.R. in the CBS television series "Barnaby Jones".

Lee Meriwether: Lee Ann Meriwether (born May 27, 1935) is an American actress, former model, and the winner of the 1955 Miss America pageant.  She is known for her role as Betty Jones, Buddy Ebsen's secretary and daughter-in-law in the long-running 1970s crime drama "Barnaby Jones".  The role earned her two Golden Globe Award nominations in 1975 and 1976, and an Emmy Award nomination in 1977.  She is also known for her role as Herman Munster's long-haired wife, Lily Munster, on the 1980s sitcom "The Munsters Today", as well as for her portrayal of Catwoman, replacing Julie Newmar in the film version of "Batman" (1966), and for a co-starring role on the science fiction series "The Time Tunnel".  Meriwether had a recurring role as Ruth Martin on the daytime soap opera "All My Children" until the end of the series in September 2011.

William Conrad: William Conrad (September 27, 1920 – February 11, 1994) was an American actor, producer, and director whose career spanned five decades in radio, film, and television.

Cannon (TV series): Cannon is a CBS detective television series produced by Quinn Martin which aired from 1971 to 1976.  The primary protagonist is the title character, private detective Frank Cannon, played by William Conrad.  He also appeared on two crossover episodes of "Barnaby Jones".

A Man Called Sloane: A Man Called Sloane is an American secret agent adventure television series that aired on NBC during the 1979-1980 television season.  It was a Woodruff Production in association with QM Productions, and became the final series produced by Quinn Martin's company to debut ("Barnaby Jones" was the last remaining QM program to be cancelled, in 1980).  It is also one of only three QM series not to have an announcer accompanying the opening titles (the others are "Most Wanted" and "Quinn Martin's Tales Of The Unexpected") and the only one not to have a "Tonight's Episode" card or the "Act I/II/III/IV/Epilog" formatting (although the episode titles still appear onscreen, they appear as part of the episode credits rather than during the standard opening).

Teru Shimada: Teru Shimada (November 17, 1905 – June 19, 1988) was an acclaimed Japanese-American actor who was cast most famously as Mr. Osato, a SPECTRE agent in the 1967 James Bond film, "You Only Live Twice".  His film career began in 1932 with the "Night Club Lady".  He appeared with Peter Lorre in the 1939 classic "Mr. Moto's Last Warning".  Another notable role was opposite Humphrey Bogart in the 1949 film, "Tokyo Joe".  He had an uncredited role in 20th Century Fox's 1966 film "Batman" as a Japanese Delegate, and as Mr. Kurawa in Cary Grant's final film, Walk, Don't Run.  He also appeared in an episode (titled "And Five of Us are Left") of the 1960s American television series "Voyage to the Bottom of the Sea" in 1965.  That year he also made a guest appearance on "Perry Mason" as Dr. Maseo Tachikawa in "The Case of the Baffling Bug."  In 1970, he had had a leading role in an episode of "Hawaii Five-O" (titled "The Reunion").  He later retired in the mid-1970s following appearances in "Barnaby Jones" and "The Six Million Dollar Man", and died in Encino, California in 1988.

Hank Simms: Hank Simms (May 25, 1923 - August 7, 2013) was a voice actor and announcer, best known for narrating the opening credits of Quinn Martin TV shows, including "The F.B.I.", "Barnaby Jones", "Cannon" and "The Streets of San Francisco".  He was also hired to imitate his distinctive announcing style in the opening credits for the satirical TV series "Police Squad! ".

Nellie Bellflower: Nellie Bellflower (born May 1, 1946 in Phoenix, Arizona) is an American actress and voice artist who provided the voice of Princess Ariel in the Ruby-Spears animated television series "Thundarr the Barbarian".  She has also been in "The Last Unicorn" (voice), Rankin/Bass "The Return of the King", "Americathon", the miniseries "East of Eden", and guest roles on various TV shows such as "Barnaby Jones", "Barney Miller", "Starsky and Hutch", and "Happy Days" as Fonzie's ex-fiancée Maureen Johnson, a.k.a. "The Lone Stripper", in the Season 2 episode of the series titled "Fonzie's Getting Married" (episode #13).  Nellie has been involved in movie production with three projects: "The Girl in Melanie Klein" (2008), "Miss Pettigrew Lives for a Day" (2008) and "Finding Neverland" (2004), for which she was nominated for an Academy Award as Producer for Best Picture.  She is married to Michael Mislove.

Barnaby Jones: Barnaby Jones is a television detective series starring Buddy Ebsen and Lee Meriwether as a father and daughter-in-law who run a private detective firm in Los Angeles, California.  The show was introduced as a midseason replacement on the CBS network and broadcast from 1973 to 1980.  Halfway through the series run, Mark Shera was added to the cast as the cousin of Ebsen's character, who joins the firm.  William Conrad guest-starred as Frank Cannon of "Cannon" on the first "Barnaby Jones" episode, "Requiem for a Son", and the 1975 two-part crossover episodes, "The Deadly Conspiracy".  The series was produced by QM Productions (with Woodruff Productions in the final two seasons).  It had the second longest QM series run (seven and a half seasons) following the eight years of "The FBI".  The series bore the Quinn Martin trademark where commercial breaks divided each episode into 4 "Acts" concluding with an epilogue.  The opening credits were narrated by Hank Simms.

Joel Fabiani: Joel Fabiani (born September 28, 1936, Watsonville, California) is an American film, television and theater actor.  Generally most famous for the British cult classic "Department S", he is also known to fans of 1970s cop shows for guest starring in "The FBI", "Barnaby Jones", "The Streets of San Francisco", "Banacek", "Cannon", "The Rockford Files", "Starsky and Hutch" and many more.

Supporting paragraphs: Barnaby Jones William Conrad
Answer: William Conrad