Heather moved closer to the map with a red ruler in her hand and pointed. “Humor me, let’s do this one more time. The first murder was Lisa Eng on 95th Street, right? Next, Carly Faircloth on 104th Street, which means our perp went uptown by nine blocks. Third, Nicole Barrett on 96th Street, which means he goes back downtown by eight blocks.”

“Then in March it was Rosie Florio on 97th and Columbus,” said Daryl.

“Which is only one block north of the previous murder,” said Heather. “The killer stayed in the same neighborhood. That’s significant, right?”

Daryl shrugged his shoulders. “I’ve looked at this thing so many times, I don’t know what’s significant anymore.”

“The fifth victim was Michelle Rothberg on 103rd and Amsterdam; and victim number six, Katie Tierney, on Central Park West and 100th Street,” said Heather, walking in front of the map like a college professor giving a lecture. “The killer goes uptown then downtown then uptown then downtown. A big zigzag. Maybe that’s something? Maybe that’s part of his pattern?”

“If it is, I don’t know what it means. Any theories?”

“Not a clue,” said a frustrated Heather plopping down in her desk chair. “We’ve checked every retailer in the areas surrounding each crime scene and there’s no connection.”

“What’s your gut on the teacher in the park as a seventh victim?” said Daryl. “I’m not a hundred percent on that.”

“Part of me says yes and part of me says no. Medical examiner said the strangulation technique appears the same but everything else is wrong.”

“Let’s re-interview a few people,” said Daryl as he picked up a file on his desk. “We’ve missed something. Tomorrow, we’ll go back over to Katie Tierney’s neighborhood and rattle some trees until something falls out.”

As the two detectives dug into their own individual paperwork, a bald, middle-aged mailman who was clearly lost entered the police bullpen.

“I’m looking for a Detective Daryl Williams,” said the postman loudly, lugging his overstuffed mailbag, visibly sweating through his face mask. “It’s so hot outside and this mask keeps all the heat in. No global warming? Ha! I’m dying out there.”

“Wait until August,” said a young officer passing by. “We’re all going to bake in those masks. Be glad you’re not a traffic cop standing in the sun.”

“I’m Williams,” said Daryl raising his hand.

“The man of the hour. I’ve got two letters for you that need signatures,” said the postal worker, pulling two envelopes out of his bag and handing them to Daryl.

As the detective reached for a pen, the mailman looked around the busy room. “Looks like you’ve got a lot going on here,” he said.

“You could say that,” said Heather without looking up.