"The Bullet in the Brain" is episode eleven of season six of Bones, the forensic drama television series loosely based on the novels and life of anthropologist Kathy Reichs. In this episode, the Gravedigger is heading for her final appeal when someone blows her head off with a sniper rifle.
The Gravedigger is Shot
Heather Taffet, the Gravedigger, who was found guilty in "The Boy with the Answer", is being escorted to the courthouse for her final appeal (she is on death row). Sweets is accompanying her on the transport, to fulfil her request to have psychological counsel. The outside of the courthouse when she arrives is full of protesters (as there is a vague chance her appeal might work), but the gate to the parking garage is closed and won't open, so the prisoner transport is arriving at the front. The Gravedigger is taunting Sweets in the transport but, as she steps out of the transport and is being escorted to the court, suddenly Sweets gets covered in blood. The Gravedigger is dead, from a sniper shot, with her head in bits (although the actual kill is never seen - it was probably very messy).
A Sniper Shot
Brennan arrives on the scene - the bits of the Gravedigger's skull are going to the Jeffersonian. Booth finds the bullet, which after obliterating Taffet's head has deeply embedded itself in a wall. He says that it was a powerful rifle which, given his own experience, is a professional opinion. Sweets is more than a little shaken, but is also happy that the Gravedigger can't hurt anyone else (but he has problems with what the Gravedigger said to him in the transport).
Lots of Suspects, but they Lack the Skills
Booth says the shot wasn't heard, but it wasn't a silencer, just probably long range. There are quite a few people who would like the Gravedigger dead - including, Caroline says, Brennan's father, Max. Who did try to shoot her once (and Brennan does consider this a possibility - and he isn't out of the country as he is supposed to be). As well as the families of the victims, Taffet put quite a few people away as a prosecutor, who would perhaps also want her dead, and there are some lawyers she met in court who also don't like her. The father of two of the victims was also filming what happened.
A Professional Hit
The bullet was pure copper which is rather unusual. The bullet is also handmade, and the shooting was from so far away, that Booth says it was a professional hit. The shot appears to be from nearly a mile away, which is not merely good but really, really good. Hodgins wants to give the killer a gift basket. Angela finds this understandable, but a little concerning.
Booth Must Know the Shooter
The apartment the sniper shot from is found, and Brennan says that the sniper is so good that Booth, given they are members of a small, elite, community, must know the shooter. He agrees; even if he doesn't know specifically which one, yet, he must know the person. The resident of the apartment is still in, but sealed in the bath full of drain cleaner, dead. The woman was dead long enough that the shooter knew about the hearing well before it was announced, which suggests inside information.
The Gravedigger is Not Mourned, but There Was Another Victim
All this to find a sniper that killed someone who no-one is really upset about being dead. What will happen when the shooter is found? And they were probably paid for the job as well. The sniper also killed someone else, though - the woman whose apartment he took the shot from. That is a different story.