Joan hates bombs. They don't leave much useful evidence.
The explosion would have been bad enough, but the resulting fire had wiped out any trace evidence that would have led to the bomber. They'd identified Allison Pitzker based on the dead security guard's records – she was the only other employee working late that night.
They'd have to check dental records to be sure. Most of Allison's body was particulate matter. Joan was intensely aware of the soot on her clothing and trapped in her hair. She desperately wanted a shower.
Joan had seen a lot, since she'd started working with Sherlock. She could understand crimes of passion. Anger, jealousy, revenge – those motives made sense. Bombings were the opposite.
Bombings were ice-cold crimes, meticulously, obsessively planned over days and weeks. The target was all that mattered. Bombers were indifferent to anyone else caught up in the blast, as if their world were populated by cardboard cut-outs.
Bombers didn't care about Allison Pitzker, the security guard, or Eugene's favorite CSU specialist, Nicole. With the DANTE test fresh in her mind, Joan realized this type of crime bothers her the most. The ones exhibiting the complete lack of empathy of psychopaths, the Moriarty organization, and everyone operating in Morland's world of high finance.
'Collateral damage.' Yeah. That's the other thing she hates about bombs.