I investigated the rape of a 14 year old girl many years ago. The incident happened in the winter, behind a garage on the grounds of a church. The offender was wearing a ski-mask during the attack, and we initially thought there there would be very little the girl would be able to provide us in the way of a physical description.
But I spent a long time trying to obtain even minuscule amounts of information from her, and she was very good at remembering details. I was rather surprised at how calm she remained throughout my interviews with her. She and her family cooperated with us completely.
She described the details to a police sketch artist, and the composite drawing ended up looking like a black and white version of a Pacman ghost.
The other detectives made fun of my drawing, telling me I had wasted the sketch artist's time, and that the drawing was of no value at all.
But I kept it pinned on my bulletin board all the same, and I was determined to catch the SOB that did this to the girl.
Several days after the incident I caught a break. The victim was able to give us a good description of his clothing, and in addition to the ski mask , the type of coat he was wearing. It was a ski jacket type and was somewhat distinctive with bright colors and stripes. One of our officers saw a guy shoveling snow, and remembered the description of the ski jacket. So he forwarded that to me, and I did some background on other encounters we'd had with him.
Also, the boots the offender was wearing at the scene of the crime left sole impressions in the snow. We photographed those impressions when we processed the scene. When I went to his house, I noticed some of the same footwear pattern impressions in the snow. Things just started to fit together. I was able to develop a suspect, but I had nothing close to probable cause to charge him. The guy lived not too far from the police station.
I stopped by his house to talk to him, and I asked him if he'd come to the police station to talk about a case I was investigating. I did not tell him what it was about, and he didn't ask.
He very confidently said yes, and he drove to the PD on his own.
In my office, I read him the Miranda warnings. I told him I was investigating the rape of a young girl. He said he didn't know anything about it.
I told him I knew he was lying, and that I had his picture. He said, "Prove it, pig."
Suddenly, I knew I had him. His response was not a denial, it was a challenge.
From my desk drawer I pulled out the Pacman sketch, and I said, "This is you."
He literally wet himself, then started crying. So I switched to "nice cop" mode, and he gave me a full written confession. The other detectives were very impressed.
He served a long time in prison. Last I heard he was out on parole, but would have to register as a predatory sex offender for the rest of his life.