UPDATE: He has been confirmed as a veteran.
The latest mass shooter in the United States (in Dallas this morning) has a video on his Facebook page [UPDATE: The video has been removed] in which he claims to have been in the U.S. Army. Statistically, that’s likely to be true. Disproportionately, mass shooters have been trained as mass shooters by the U.S. military.
In researching that finding, however, I also found that another large percentage of mass shooters imagined themselves in the U.S. military. Some tried to join and were rejected. Others simply dressed the part and played the part. In fact, the vast majority of mass shooters were either trained by the U.S. military (including the JROTC) or were engaged in acting out a fantasy of being in the U.S. military. So it is possible that we will find the latter to be the case in Dallas today.