Cannon

Cannon was a detective series which ran on CBS from 1971 to 1976. It starred William Conrad as the overweight detective Frank Cannon, who had resigned from the LAPD and become a private detective. He charged high fees to his well-to-do clients so that he could work for poorer clients at little or no charge. He also used it to indulge his high-priced lifestyle, which included maintenance on his Lincoln Mark IV, which was frequently wrecked.

The series was a Quinn Martin production, and featured many of the company's well-known stylistic quirks. Cannon marked the first time a QM series aired on a network other than ABC.

Frank Cannon frequently crossed over to appear on Barnaby Jones, another QM series which ran concurrently with Cannon on CBS between January 1973 and the latter's cancellation.
From: Wikipedia.org

Linked from nostalgia and retrospection posts:

• CLASSIC TV — C
• EMMY AWARDS