An up-to-date accounting of Jose Guerena's murder is well documented on wikipedia.
"Asleep after returning from a 12-hour overnight shift at the ASARCO Mission mine, Guerena was awakened about 9:30 AM by his wife who heard noises outside their house, later identified as flash/bang grenades deployed by police in the back yard as a diversion. He instructed his wife and 4-year-old son to hide inside a closet while he grabbed his AR-15 rifle and crouched down preparing to defend himself from whomever was breaking into his home. The Sheriff's Department initially claimed Guerena had fired on officers; at least three of the SWAT members including the team commander reported in their post-operation debriefings that they had observed muzzle flashes aimed at them from inside the house. Other officers stated they saw splinters from the doorjamb being hit by bullets. The shots that caused this were determined to come from other members of the SWAT team. "There were five officers at the door beginning to make entry into this home, when they engaged this individual that they believed was actually firing at them." Other versions of this story claim that officers started shooting after Guerena pointed the gun at them, though under questioning they were initially unsure whether he had actually moved to target them. At this point the five person team fired 71 rounds at Guerena in seven seconds, who died after being hit 22 times. An investigation revealed that Jose had not fired his weapon. The AR-15 rifle Guerena allegedly pointed toward officers was found loaded, but with the safety engaged."
Local Media Coverage
Russian Today Coverage
President Obama's reaction to the Tucson shooting - same jurisdiction, different victims