It sounds like he was one messed up kid from long ago, almost a ticking time bomb waiting to explode.
I do believe Prozac probably sent him over the edge.
Police found that Jose Reyes knew his father owned two guns, but "both were unequivocal in their statements that Jose was not familiar with the guns and he had never been shown how to shoot either weapon." The report stresses that the parents even discussed it in the police lobby, without knowing they were being recorded.
Reyes' parents also were aware that he played violent video games, but did little to monitor his playing. They also did not monitor his internet usage or what was on his cell phone. His parents were unaware of the images he stored on his phone, including images of the Columbine shooters and other school shooters.
Some video about the disclosure he had been prescribed Prozac: