“Drugged?”

“That’s our bet. We took blood and urine.”

“Sexual assault?”

“Doc said she saw evidence of recent sexual activity, but the girl was out of it, so we couldn’t ask about consent.”

This all sounded strangely familiar to Niki. She pointed to a table and the two of them moved to take seats. There had been other women in the river. She worked the memories out of the dust.

“Fully clothed?” she asked.

George tipped his head, curious. “Yeah.”

“No ligature marks?”

“None.”

Niki took a moment to think, to remember them all. The most recent one had been two years ago. It hadn’t been her case, but she remembered how cavalier Lieutenant Briggs had been when he assigned it to the other detective. “I’ll bet fifty bucks that she just broke up with her boyfriend,” he’d said.

Curious, and disliking his assumption, Niki had done some digging and found a similar death two years before that and another two years before that. When she mentioned this to Briggs, he said, “We have enough murder cases to keep us busy; we don’t need to burn time on people who jump off bridges. These are low-priority cases. Focus on the ones we know were murdered.” She was a rookie in Homicide back then and didn’t challenge Briggs, but his offhanded dismissal stuck with her.

Niki leaned in toward George and lowered her voice. “Just after I came to Homicide, they pulled the body of a young woman from the river down near Ford Parkway. She was fully clothed, her body a mess: postmortem bruises, broken bones. Best we could figure, she went in upstream from the falls. Two years before that, another one washed ashore in Gorge Park. We couldn’t really say it was a murder versus an accident or a suicide.”

“Two victims?”

“Maybe three. St. Paul pulled a woman out of the river six years ago. Same MO: fully clothed, no ligature marks, no defensive wounds. They all had signs of recent sexual activity and GHB in their systems.”

“Okay, but GHB can show up naturally in a dead body.”

“A few years back, they came out with a new test using brain tissue. GHB doesn’t get into the brain unless it’s ingested. They did that test on the girl from two years ago, so we know she definitely ingested it. Whether it was voluntarily or slipped to her, we can’t say. What can you tell me about the one from last night?”

“Her name’s Sadie Vauk. We think she went into the river off Nicollet Island.”

“Find anything on the island?”

“Some tire tracks. They ran along one of the walking paths. Stopped near a gap in the trees. We made a cast of the tread print. No surveillance cameras in that spot, but we have requests in at some of the businesses around the area. Maybe we’ll catch a glimpse of something. We know what time the security guard found her, so we have a pretty tight window.”