There were guesses, though. Some thought they were caused by a can of chewing tobacco. Others suggested they were imprints of crushed soda cans. They had ideas, but nobody ever actually took the time to find out exactly what they were.

I took the exact measurements recorded in the autopsy, and I re-created those circles precisely. I concluded that I was looking at some kind of a lid, but I didn’t understand why it was flat on one side.

I started by going to the local Walmart store. I didn’t want to go broke buying every circular item in town, so the only way I could find out what caused the impressions was to walk into stores and press whatever I could find that was circular against my body. I’m sure I made quite a spectacle.

“What is that blonde doing in the hardware section, picking up item after item, pressing the tool onto her arm, saying, ‘No, that’s not it,’ throwing it back, and then repeating it with another one?”

I started running out of room on my arm, so I pressed items against my thigh. Then I went through the neighborhood drugstore, continuing with press tests. This was where I located a one-ounce can of Skoal snuff, which several people thought might be the matching product. When I pressed it against my body, it made two rings, measuring.5cm apart. But the circles on Sarah’s body were 1cm apart. The soda can concept didn’t even make sense. It had only one outside edge.

Eventually, I wandered into a hardware store, went to the paint and enamel section, and picked up a can of Minwax.

“That looks like the right top,” I said aloud, to no one in particular.

By that time, I was pretty aware of what kind of impressions various lids would make just by holding them. The Minwax can’s lid is embedded into the top of the can, making an airtight seal, so I couldn’t pull it off in the store. But boy, it sure looked right. I turned the can over and pressed it against myself, and I said, again out loud, “This has got to be it.”

I took out my tape measure and measured the lid area, and it had identical measurements to what I was seeking, the extra thin lines, and the little rim part with two double lines.

I bought the Minwax-to the relief of a befuddled clerk and several customers-and brought it home to my “lab.” In order to properly do the lid press test, I had to pry the lid off the can. As the top is forced up and off the can, one side flattens out a little. I took the lid and placed it next to the photos. It looked exactly like the circles in the pictures. I double-checked the measurements of the lid, and the measurements were exactly the same. The flattened edge of the lid top fit into the twelve-to-three spot of the clock face. I determined a couple of Minwax can lids were indeed what left the mysterious rings on Sarah Andrews’s bottom.

Could there be something else out in the universe that could make the same marks? Absolutely. But at a certain point, one of the things any detective or profiler has to ask is, “When do I stop looking?” The universe is a big place. I could look for every possible similar lid in all of creation, and I could spend thousands and thousands of hours doing it. But at some point, you have to stop. I stopped here because after looking through dozens and dozens of commercially available products, this one made sense to me, because we were talking about the victim being in the back of a van. What would be on the floor of a van? A lot of guys use various paint and enamel products in their work and hobbies. If they are in the painting business, if they have motorcycles, if they do carpentry, they might have a few cans of Minwax paint or enamel in their vehicle. They might have jimmied off the lid tops and tossed them onto the floor in the back of a van.

My theory was that Sarah lay on top of a couple of Minwax can lids or something very similar to them until she was dumped out of the vehicle.

SOLVING THAT MYSTERY led back to another: Why was she lying in the back of the vehicle?

There were a couple possibilities. One is that the guy killed her while he was on a break and then went back to work. If he was a bouncer at the nightclub, he might have been on a break (sometimes bouncers just vanish for a while), but then continued working until the club closed and the crowd dispersed. He could have been hanging out until four in the morning. (Officially, closing time at the nightclub was two a.m. No one was ever sure if it actually closed at that time, however.)

One of the possible suspects I suggested to the police worked at the nightclub. He was a bouncer, an ex-con with a history as a violent offender and a burglar, and he had been in and out of prison. A big guy, he fit the profile.

So it’s possible that Sarah went out to the van to smoke a joint with the bouncer and during that time, he took a fancy to her and wanted to have his way with her. She fought him off, which made him angry. He lost his composure, threw her in the back, and raped and strangled her. All of that takes a lot less time than people ever imagine, ten minutes, fifteen minutes max, because we are talking about someone who acted in a rage-and who was likely on the clock. He was what profilers call a power rapist. He wants what he wants and he wants it his way on his timetable. He gets angry when he doesn’t get it, and then he follows through in a forceful, violent way. That’s a power offender. He wants to prove his masculinity. “How dare you turn me down?” That kind of guy doesn’t take long to rape and murder somebody. If he could have controlled her, he might have done less damage to her, but Sarah was known to be a fighter, not someone who would give up without a struggle.

People who don’t know better imagine he must have been at this for a couple of hours. But no, he needed to be gone for only fifteen or twenty minutes, and then she’s dead in the back of his vehicle. He throws a blanket over her so nobody can see her if they peep in his van windows. He goes right back into the club, cleans up, finishes out the night, and by early morning, with the club closed and everyone gone home, he can go back to his van, now the only vehicle left in the lot.

At that point he could have picked her up by an arm and a leg, flipped her out of the van, and she would have dropped onto the ground. The police thought she looked posed. I didn’t think so. If a fairly strong fellow shoved the body to the edge of the car, he could pick her up, swing her body out from the van, and she would have landed just as Sarah did.

Then he would drive away and toss the rest of her clothes-and maybe some of his own-when he realized he still had incriminating evidence in his van.

The bouncer is just one possible suspect and the story above just one possible scenario. Sarah could have left with someone else who was at the club, she could have left and been on the way back to the club with someone. I couldn’t say exactly who the killer was but I could tell you he had some connection to the area around the nightclub, wasn’t a total stranger to Sarah, did some kind of work painting or fixing stuff, and was relatively strong. And we were looking at only one killer, not two or three, or a gang. Just one sick monster.

We were looking at somebody who likely did know Sarah, but not necessarily well. It could have been a casual acquaintance, but the behavior suggested an experienced sex offender. This had nothing to do with drugs.

If an investigator or profiler deduced this originally, the police could have run away from all those other silly theories and focused on sexual psychopaths who were in the vicinity of the nightclub that night.

WAS THE MURDERER someone from the same base as Sarah Andrews? Was it an army guy?

Sarah had bite marks on her breast and hand, and who, on the base, if they had killed Sarah, would want to display her body so it would be found within two hours?