Sam had come ready for this. She placed photos of the women who’d been raped and murdered on the table in front of the mayor, introducing each of them to her. “Audrey Olsen was a teacher who devoted her spare time to teaching English as a second language to immigrant children. She’d lived with her boyfriend, Wes, and had dated him for five years, since they were nineteen. He told me he was planning to propose to her on Valentine’s Day, which was, incidentally, the day they met.

“This is Ling Woo, a biomedical engineering graduate student at Georgetown, the first of her family to attend college and, by all accounts, a brilliant scientist. She’d recently started running again as a New Year’s resolution. Both women were assaulted and murdered in Rock Creek Park. These other two victims were ‘lucky’ to escape with their lives but are dealing with trauma that’ll stay with them forever. Kaitlyn Oliver told us she doesn’t feel safe anywhere, even in her own home. And Moira Kaull is so traumatized, we’ve yet to be able to interview her. These four victims have one thing in common—they were all attacked from behind by the same man in the vicinity of Rock Creek Park.”

“What can I do to help get this guy?” Brewster asked.

“We’ve exhausted our usual investigative techniques, having spent countless hours canvassing the park and surrounding neighborhoods, reviewing thousands of hours of video, interviewing forty potential witnesses and thoroughly investigating each of our victims.”

“Oh Lord. You have nothing?”

“Nothing except his DNA, which doesn’t help us unless the man has been arrested in the past, which he hasn’t been. We’d like you to authorize an exception to the District’s prohibition on using familial DNA searches in police investigations and allow us to run his DNA for a familial match.”

Brewster was shaking her head before Sam completed the sentence. “Absolutely not.”

“We understand and respect the many objections to the use of FDS,” Sam said. “However, we’re at a standstill in this case, and we believe the killer is becoming more confident because he’s getting away with what he’s done. He knows he’s not in the system. He knows we’re not any closer to him today than we were after the first assault. He’s emboldened by that reality, and he’ll kill again unless we stop him. You can help us stop him, ma’am.”

Brewster sat back in her seat, deflated. “I have so many concerns about this technology, which is why I wrote the resolution that outlawed it. A majority of the people with DNA on file are minorities, which stacks the deck unfairly.”

“I realize that and agree with your objections,” Sam said. “I’m not asking for a rollback of the resolution. I’m asking for a one-time exception.”