The humanoid people of Tanuga IV, whose legal system presumes an accused person guilty until proven innocent, as Riker discovers in A Matter of Perspective.
The Tanugans are the inhabitants of Tanuga IV, seen in the Next Generation episode A Matter of Perspective. The Federation has been funding the Tanugan scientist Dr Nel Apgar, who is trying to develop a converter for Krieger waves, a promising new source of power.
In 2366 Apgar's orbiting research station explodes just as Riker beams away, and the Tanugan chief investigator Krag arrives to arrest the commander for murder. Under Tanugan law a suspect is guilty until proven innocent, so Picard holds an extradition hearing in which the holodeck recreates the conflicting accounts of Riker, Apgar's wife Manua and his assistant.
The recreations themselves reveal the truth. Apgar had secretly completed the converter, meant to sell it as a weapon, and died when his attempt to kill Riker with it was reflected by the transporter beam.