Doctor Kila Marr was a human xenologist and former resident of the Omicron Theta colony. She had one son, Raymond, nicknamed "Renny" who was killed in an attack on Omicron Theta by the Crystalline Entity in 2336.
The Enterprise set course to pursue the Entity after it was located and Marr wanted to make preparations to destroy it once it was found. Captain Picard objected, feeling it would be better to try to communicate with the Entity and attempt to reason with it before resorting to violence.
She reluctantly agreed to work with Data again, this time to develop a way to use graviton pulses as a means of communication. The Enterprise eventually caught up to the Crystalline Entity and began emitting graviton pulses in an attempt to communicate. The pulses worked, and the Entity began responding with a series of its own pulses. However, Marr, blinded by vengeance and remorse over Renny's death, initiated a continuous graviton beam and then locked out the controls. The beam caused the Entity to vibrate rapidly and eventually shatter, destroying it. (TNG episode: "Silicon Avatar")
In 2380 when the USS Titan would encounter more Crystalline Entities, Captain William T. Riker did not want to allow the Pa'haquel to obtain knowledge of how the entities responded to graviton beams because he was fearful that like Marr, they would use the beams as weapons to destroy the entities rather than attempt to communicate. (TTN novel: Orion's Hounds)