A line of Sleater-Kinney fans wrapped around the Showbox before the doors opened on Sunday night, September 29. Young guys and girls chatted and kept an eye on the door, waiting for the all-ages show.

Sipping whiskey with two friends inside Showbox's streetfront bar, the Green Room, I chatted about the guy I was waiting for.

The doors opened at 7:00 p.m., and impatient Sleater-Kinney fans streamed into the club. But the man I was waiting for didn't show until 8:00 p.m. As he approached the club, I grabbed security.

The man in question is the Asian man we've written about before, for allegedly sexually assaulting women at clubs. I had the misfortune of standing in front of the short guy, 40-year-old Hyon Kim from Auburn, at last December's Sleater-Kinney Showbox shows. Kim kept thrusting into me--and my friends--at those shows, but I ignored it.

It wasn't until last June's Capitol Hill Block Party, when I saw Kim again, that I realized what was up: At the Block Party's Sleater-Kinney show, Kim was next to me, pants unzipped. Partially hidden under his shirt, the guy held his erect penis and kept thrusting it into the girls in front of him. Two girls reported the assaults and Kim was arrested ["Sex Offense at Capitol Hill Block Party," In Other News, July 18].

But since the Block Party, Kim has been spotted at other clubs--like Graceland's August 5 Oops! Tour--doing the same thing with his dick. Assuming he'd show up again for Sleater-Kinney, the Showbox wanted to be ready. Jonna McCurry, a security gal with long black braids, talked to a private investigator. The PI, a tall and stocky man who's a process server by day, was eager to catch the guy with his pants down.

The pair coordinated a plan: I would watch for Kim from the Green Room window, security would keep an eye on him all night, and the covert PI would carry a night-vision camera to get evidence of the guy's gross antics (or at least a photo, so security at other clubs could know exactly what he looks like). Our sting operation was more successful than we could have imagined.

When Kim walked in at 8:00 p.m., I flagged security and they radioed McCurry. I hurried into the club to point him out. "Even if it's not him, we'd rather be safe," McCurry said about the surveillance. After a few minutes, Kim started working his way into the crowd.

He had a dozen pairs of eyes on him. It was a twisted operation: A girl would have to be molested by the man--or he would have to expose himself--in order to have the police arrest him.

The guy was apparently well behaved during the opening bands, the Quails' rock set and Shannon Wright's melodic show. But by Sleater-Kinney's 10:00 p.m. set, he wiggled his way to the front of the stage, behind two indie-rock girls who were planted near guitarist Carrie Brownstein's mic. Halfway through the set, tall security manager Dave Hughes got into the crowd and stood by the creepy man. Meanwhile, the bruiser PI, who looked a little out of place in the Sleater-Kinney crowd, passed off his camera to a less-conspicuous girl, who sidled up next to Kim and started videotaping.

Just before 11:00 p.m., the girls in front of Kim started whispering to each other and glaring at him. A few minutes later, the man ran. The girl with the video camera and I chased him through the crowd to the club's front desk, where security was waiting. Hughes caught up and led the man into the manager's office.

Two cops arrived and asked the man if he knew why he was being detained. "Because I like to expose myself," Kim replied, according to the police report. He admitted to touching the girls in front of him with his penis, and he was arrested on charges of indecent exposure and assault. At press time, he hadn't had a formal court appearance.

After the band finished its encore, the two unlucky targets stopped by the front desk to identify the man. The cops asked 18-year-old Lindsay Wengler if Kim was the right guy. Crying, she nodded.

A man near the door ceremoniously presented Wengler with a special-edition Sleater-Kinney poster. "You're a hero now," he told her.

amy@thestranger.com