Play dead

SEVENTY-TWO

1:19 AM

They received the file via e-mail. Jessica opened the graphic program on the laptop. Moments later the screen showed a section of North Philadelphia. It was an aerial photograph of a zone that included all the crime scenes.

What tied these four buildings together? What had made their killer choose these locations?

They were all abandoned properties. Two numbered streets; two named streets. Earlier, Tony Park had run the street addresses. He had tried a hundred permutations. Nothing had leapt out.

They looked at the front elevation of the crime scenes. All four were three stories tall; three were brick, one wood. One, the Eighth Street address-where Caitlin O'Riordan had been found-had a corrugated metal roll door. All had boarded up windows on the first floors, all were covered in graffiti. Different graffiti. Three had rusted air conditioners lag-bolted next to the front windows.

"Ninth Street and Cambria have panel doors," Jessica said. Byrne circled the doors on the digital photographs of the buildings. Two buildings had steps, three had awnings. He circled these, too. Element by architectural element they compared the buildings. None of the structures were exactly alike, none were completely different. Different colors, different materials, different locations, different elevations.

Jessica looked at the support pole in front of the door on Eighth Street. A support pole. She looked at the other buildings. All three had at one time had support columns in front of the entrance, but now only had sagging, slanted rooms above the entry. It hit her. "Kevin, they're all corner buildings."

Byrne put four photographs on the hood of the car in front of the laptop. Each crime scene was at least part of a corner building in a block of four or more structures. He compared the photographs to the overhead shot on the LCD screen.

Pure geometry.

"Four triangles," Byrne said. "Four buildings that appear to be triangles from above."

"It's the city," Jessica said.

"It's the city," Byrne echoed. "He's making a tangram puzzle out of the city of Philadelphia."