The Bullet in the Brain - S6-E11
Factual error: Bone mentions Booth holds the "official record for the longest shot, almost a kilometer", and Booth corrects her to "over a kilometer." The record at the time was actually well over 2km, held by Corporal Rob Furlong, a Canadian sniper (since been beaten, it currently stands at 3.5km). In fact plenty of sniper kills had been recorded at over a kilometer since the late 19th century.
Answer: Answering my own question here but, having contacted various people involved in the production of Bones including Kathy Reichs, Hart Hanson, Eric Milligan, and Deirdre Lovegood who portrayed Taffet onscreen I finally have the answer. No-one know how she did it due to her constantly working alone. And she never revealed this information before her death.
Ssiscool ★