>> dylan spellman. he lived just three blocks from the crime scene and chaves also noticed a striking resemblance to the sketch christine helped draw of the gunman. >> we started trying to get background on him. >> quick computer searches revealed he had a criminal past. >> he had just been convicted of a violent crime. armed robbery in nevada. >> yeah. >> that nevada armed robbery occurred in 2010. a year and a half before the shootings. spellman and some accomplices broke into a home and held a family hostage before robbing them and taking off. >> anybody get killed? >> no. >> and at the time of the shootings in 2012, dylan spellman was in the coarea awaiting stensing fawai awaiting sentencing for the robbery. >> what intrigued chaves were unusual similarities between the nevada crime and the shootings in texas. >> we start going through the case file we started seeing more and more things lining up with what we're looking for. >> for example. >> the use of numbers. >> remember christine had said the