with the army, that he was only given 24 hours to grief for her in puerto rico. the base commander could not address that particular issue but did say yesterday there is very strong evidence that lopez's unstable psychiatric condition was the fundamental underlying cause for his rampage. and the general trigger event was likely that confrontation here on post wednesday afternoon. >> it was mentioned yesterday that there may have been a verbal altercation with another soldier or soldiers. there is a strong possibility that that in fact immediately preceded the shooting. >> reporter: another key question here, jon, if this was not premeditated why was he carrying a hand gun in the first place. he was not authorized to have it on post and why did he buy it and bring it with him to fort hood? jon: some of the answers i suppose could be on social media. he was active on social media, right? >> reporter: yeah he was. he posted some pretty chilling