Tom Caron is a drummer for his high school's pep squad. He's teased relentlessly by bullying classmates. Tom Caron is a killer. Glenn Martin (guest star Joey McIntyre of New Kids on the Block and Dancing with the Stars fame) is a popular teacher at Tom's school. He loves to hop up onto the stage at the local bar to belt out a few karaoke tunes during his free time. Glenn Martin was murdered by Tom Caron. The question is... Why?
Detective Angie Flynn (Kristin Lehman) is a loving, single mom and one of the best homicide cops around. She catches Glenn Martin's murder case along with her partner, Oscar Vega (Louis Ferreira). "The Creeper" is written on the wall inside the victim's kitchen suggesting the killer has given himself a nickname. Glenn's dog won't let anyone near the body. Wife, Linda, says she was asleep in another room when she heard her husband arguing with someone. By the time she got to him, he was dead. The investigative team has no idea that the killer they seek is hiding in the attic directly above their heads.
We jump back in time to learn that Glenn and Linda were having problems in their marriage. As for Tom, he engages in a practice known as "creeping" with his stoner pal, Willie. They sneak around people's homes trying to be invisible as they steal little things. Tom specifically targets his teacher's home. That's why he doesn't leave when he hears two people having sex in a downstairs room. Willie whips out a marker to write "The Creeper" in the kitchen. The boys bolt when Linda comes out of the back room with her illicit lover. Willie wants to get high, but Tom isn't done with his mission.
In the present day, Angie orders a more thorough search of the victim's house. This has Tom scrambling to escape through a vent in the roof. He struggles to open the grate with a coin before he's found. Angie notices that one of Glenn's bowling trophies is missing. It could have been used as the murder weapon. We jump back in time to see Tom sneak back into the house. He pets the dog before heading up to Glenn's bedroom. There's a struggle, though we can't quite see what's happening. Linda bursts into the room to find her husband bleeding out on the floor.
In the present, Angie realizes that the killer must have escaped via the roof. She makes her way into the attic moments after Tom narrowly escapes. Angie takes photos of the crowd out front. Tom tries to hide his face as so only his backpack can be seen. Inside that backpack is the bowling trophy he used to kill his teacher. Tom recalls the murder in his head as he attends a party being thrown by a cute girl he likes named Kristi. The two of them kiss in the hallway after Tom emotionally admits that he wishes his teacher wasn't dead.
Angie learns that Linda is having an affair with a coworker named Arman, who alibis out for the murder. She believes they are looking for a teenager. Medical Examiner Dr. Betty Rogers (Lauren Holly) is happy to show detective trainee Brian Lucas (Brendan Penny) all the cool aspects of an autopsy while Angie checks out the big teen party at Kristi's place. She runs into Tom, who says he used see Glenn at the dog park from time to time. Willie admits that he was near the victim's house the night of the murder in the hopes of getting a reward. Tom freaks when he finds out about this. His goal is to always remain invisible.
Tom is surprised to find Angie and Oscar at his house. He says Willie was creeping inside Glenn Martin's house. He plants the bowling trophy underneath his pal's bed. Willie is arrested at school. Angie tells squad room supervisor Boyd Bloom (Roger Cross) that she doesn't believe this kid is the killer. He has no motive. She's ordered to go home. Angie meets up with her son, Manny (Cameron Bright), as he races cars at a track. While there, she wonders why the murder victim's dog didn't attack the killer the same way he attacked her. It's because the loyal pooch knew the person who broke into the house. Angie realizes Tom is the killer.
Glenn Martin found a manifesto notebook Tom was keeping. He was going to turn it over to the police. Tom broke into Glenn's place to steal back his notebook. Things went south when his teacher woke up. Angie wants to know why Tom had to commit murder. The worst thing that could have happened to him was a charge of breaking and entering. That wouldn't work for someone like Tom Caron. He's the type of person who likes to be invisible.