This was multiple shots. Real hard to explain except the guy must be nuts.
And it appears that so far, no explanation of any sort has been offered.
At the very least I expected his statement to be something along the line of "She surprised me and I thought she was attacking us."
If it isn't that, then the only explanation I can think of is that he was on drugs, probably meth.
It makes people crazy paranoid.
If it is like other such cases in the US, he could be a known wolf. There were excuses made for the Fort Hood shooter even AFTER his attack saying that it would be worse than the murder of over a dozen Americans if diversity in the ranks was some how endangered.
Reports were on file about Nidal Hassan, the Orlando bisexual jihadist, the San Bernadino couple, the Boston bombers, and more...