>> i'm jill walker. >> what's going on there? >> i just tried to wake my daughter for school. she has no pulse. >> how old is she? >> she's -- she's 16. >> you said that she's nonresponsive? >> yeah. >> the call came out as a suicide, it was about 30 minutes before shift was over. >> reporter: officer nikki bules is the lead forensic technician on the case. >> when i first got there, i started my photographs on the outside of the residence. i walked in, photographed the interior of the residence. photographed the bedroom. >> reporter: a typical teen girl's bedroom. messy with clothes and beauty products strewn about. pictures and cheer trophies on the wall. but immediately officer bules notices something unusual. >> there was a hole in the wall. it appeared to be a bullet hole. at that point, i knew that it probably was not a suicide. >> it's been upgraded from a suicide to a homicide. >> reporter: lead detective allen merritt rushes to the walker home. he takes me back to the scene. >> so i'm standing outside here. the bullet hole is just about shoulder high there in the wall