. >> after surveying the crime screen, investigator chuck wheeler examines the weapon. >> it's an x-acto blade from a hobby craft box. he just took a little bit of time to put a couple of pieces of wood together to hold it in place. a raise zor blade type weapon will do a lot of damage. >> the suspect, michael ray stafford, is brought in for questioning. >> have a seat right there. do you want to tell me where you got the knifes from? >>> coming up -- >> oh, i'm innocent. >> investigator wheeler finds both the suspect and the victim unwilling to cooperate. >> the victim doesn't want to be labeled as a snitch. and i quit smoking with chantix. knowing that i could smoke during the first week was really important to me. [ male announcer ] along with support, chantix is proven to help people quit smoking. chantix reduced my urge to smoke -- and personally that's what i knew i needed. [ male announcer ] some people had changes in behavior, thinking or mood, hostility, agitation, depressed mood and suicidal thoughts or actions while taking or after stopping chantix. if you notice any of these,