Jake Randolph in "The Littlest Client" Pt. 67

"But that doesn't explain murder, does it? Unless she called Dolan and he...," I let it trail off.

Harrigan nodded. He was way ahead of me.

"And he," Harrigan said, "came back and started bumping off anyone who might be able to lead you to him."

"But why wouldn't he just try to kill me? After all, those guys used to be his friends."

"Used to be is the operative phrase, Jake. He double-crossed them. And you said that Gallagher tortured the other three beyond belief until he was satisfied they were telling the truth."

He had a point...