The Star Trek: The Original Series: The Case of the Colonist's Corpse

When Captain Kirk faced court-martial, he chose the best lawyer in the Federation -- Samuel T. Cogley, a cranky old man who prefers books to padds and people to computers.
Now, once again, it's SAM COGLEY FOR THE DEFENSE!
The planet Aneher II sits in the middle of the Neutral Zone, and neither the Klingon™ Empire nor the Federation can claim it. Under the terms of the Organian Peace Treaty, any such contested colony world will go to the party -- Federation or Klingon -- which shows it can best develop the planet.
At first the two colonies live in peace, but it's a fragile peace, one shattered when Administrator Daniel Latham, the head of the Federation colony, is found murdered, and Commander Mak'Tor, the head of the Klingon colony, is found crouched over Latham's body, discharged phaser still hot in his hand.
When Lieutenant Areel Shaw of Starfleet is assigned to prosecute Mak'Tor, Sam Cogley volunteers to defend the accused Klingon. But when Cogley's own investigation provides the prosecution with its key piece of evidence and his courtroom tactics unexpectedly backfire, can even the galaxy's most brilliant defense attorney win the day in...
The Case of the Colonist's Corpse