[PSYCHO-FREEP]

This guy was NO amateur.

There is no way anyone could gain such familiarity and deadly accuracy with a pistol in such a short time.

He was highly trained. And not many militarys train soldiers in the primary use of any pistol. They use military assault rifles and are exclusively trained as such, not to this degree with pistols.

[Strategerist]

He was highly trained

There have been a variety of mass shootings accomplished solely with handguns with significant casualties by shooters with limited training.

[BJClinton]

He was highly trained.

I'll join in the wild speculation. These kills were all at short or point blank range. He was not under fire. An hour at a gun range and hours of Counter Strike would be sufficient training.

[Spktyr]

I have to disagree here. It is not that hard to achieve decent marksmanship with a pistol at short ranges, and we know the lunatic didn’t successfully make shots that were over about 50 feet (from reports that he took shots at a janitor and other people that were down a hall - and missed, badly). Most of his kills were probably within a 25 foot radius.