The bloodstain pattern that glowed violet for me told the heartless story of him asleep or passed out drunk in front of the TV when a murderer walked in a door that apparently was never locked. Roth was struck once in the back of the head with a malt liquor bottle that the killer placed inside a trash bag he closed with a twist tie.

Bloody streaks and swipes on dirty stained dark carpet and bloody drag marks soaked into the pile led from the living room to the basement door, and then blood was plainly visible where one would expect it to be if he were an accidental death. Drips and smears were on the six concrete steps leading to the basement, his unconscious body pushed down the stairs and then kicked and stomped where it landed. The killer made sure Roth wouldn’t survive and assumed no one would entertain the possibility he was a homicide, that it would never enter our minds.

“He did make some effort to disguise what he’s done,” Benton points out, as we pass the boathouse, the old Polaroid building again. “He could have just showed up late at night and shot him, stabbed him, strangled him, but that would have been obvious. He got some of it right but not the rest of it, because he’s unable to anticipate what normal people do.”

“He can’t imagine any of us caring.”

“That’s right. Someone empty, hollow. He’s probably seen him around here.”

Benton suspects the killer has noticed Roth in Cambridge, has been aware of him for months, observing the handyman wandering about looking for work and digging through trash cans and recycle bins, sometimes pushing a grocery cart. This killer is aware of everyone when he’s stalking his next victim, Benton says. He prowls, cruises, researches, observing patterns and calculating. He does dry runs, feeding his cruel fantasies.

But that doesn’t mean he knew who Howard Roth was by name. The killer forged a hundred-dollar check that he likely sent in the mail as he continued to pay Peggy Stanton’s bills long after she was dead. But that doesn’t mean he had a clue that the Howard Roth whose check he wrote was the homeless-looking man he saw rooting through the trash in Cambridge.

“What I’m sure of is he killed Roth when he did for a reason,” Benton says. “This was an expedient homicide devoid of emotion.”

“Stomping and kicking him seems rather emotional.”

“It wasn’t personal,” Benton replies. “He felt nothing.”

“It could be construed as angry. In most stomping cases, there’s rage,” I reply.

“He felt he needed to get it done. Like killing a bug. I’m wondering if he’d been to her house recently, if Roth had.” Benton’s looking down at his phone again. “Maybe wanting his money, and it was bad timing.”