Some of the police officers at the scene of the shooting have "HBT" on their hats and Kevlar vests, this stands for Hostage/Barricaded/Terrorist, which was the name of one of the Chicago Police Department's elite tactical units, which was part of the Critical Incident Response Program; other units in the program included the bomb squad and high-risk warrant/arrest unit. In January of 2012 the Chicago PD reorganized the Critical Incident Response Program into the Special Weapons and Tactics (SWAT) Incident Program, as the term SWAT is the most commonly known name for a police tactical unit.
The reason the bomber had chicken wire wrapped around his torso is for its use as shrapnel. When the bomb detonates the wire would be shredded into small pieces and shot out in all directions, essentially like a 360 degree shotgun blast, the small pieces of wire would injure and potentially kill people far outside the blast radius of the explosion. Other items bombers typically use as makeshift shrapnel are nails and ball bearings, sometimes they are soaked in a blood thinner like warfarin greatly increasing their lethality.
The song Carter tests his CD with is "Ruby" by Jimmy Smith.
There is absolutely no reason to give a horse a pat on his backside to persuade him to exit the trailer. Just pull his halter and he'll come right out.