She was one of the last constabulary officers in this virtually crime-free society, which had outlawed violent thoughts. She and Tuvok became acquainted when the USS Voyager visited the Mari homeworld. Both respected the way their respective societies eliminated violence, and both agreed to further activities aboard Voyager.
Meanwhile, B'Elanna Torres was framed for illegeally transmitting violent thoughts, which had caused further violence. Shortly after, Nimira arrested Torres for violent thoughts. She intended to use an engramatic purge on Torres, which could cause brain damage, in order to remove her violent thoughts.
Tuvok, suspicious of the true cause of violent incidents involving Torres' thoughts, mind-melded with Torres and found out that a man named Guill had probed her mind. It was discovered that Guill was a dealer in a black market of violent imagery among the Mari. Nimira was at first reluctant to accept the evidence, but when Guill admitted his guilt after Tuvok inflicted pain on him through a mind meld, she agreed to take him into custody and to release Torres. (VOY: "Random Thoughts")