A woman who identified herself as Martin's mother said he was "way too stressed out."
In 1994, Martin was convicted of stabbing a woman in Mississippi, according to court records. Six year later, he was found to have illegally modified his car speakers and received a notice for "squealing or screeching tires."
Martin lived in Aurora, but it was unclear if he was a life-long resident.
Two of four police officers who first responded to the incident and entered the building were 'fired upon immediately' by Martin. He was reportedly armed with Smith & Wesson handgun. The initial gunfight lasted five minutes.
Preliminary evidence suggested Martin originally fired from a window. The entire duration of the incident lasted one hour and 35 minutes.
Police have yet to determine a motive and were looking at his criminal history.