. >> the victim, a 22-year-old prostitute named janet dolan, was killed with a single gunshot before her body was transported, doused with gasoline and set on fire. >> it would appear to be more like an execution or message-style murder when you have somebody shot and wrapped up and burned. >> but while the similarities between the cases were striking, so were the differences. >> first of all, we had a female versus a male victim. >> david nixon was wealthy, had no criminal history and was not the type to put himself in harm's way. janet dolan was just the opposite. >> she probably put herself in some very strange situations with people she did not know. >> and janet's murder seemed to be a crime of opportunity, not something that had been planned. police concluded it was possible but highly unlikely the cases were connected. but investigators got a break when they discovered forensic evidence at david nixon's crime scene. there were tire impressions found within ten feet of david's body. >> it obviously, we believed, was the vehicle that transported him there. >> the tracks were fro