If this is not a homegrown nutjob, it may be possible that they may not be releasing his name, as it may tip off any of his buddies that may be elsewhere in this country or off shore......There may be info in the residence that will lead investigators to his buddies.....So this may be the reason they may be tight mouthed about his ID....
Just speculation.......A wild guess.
Anything is possible, but this is a suburban-rural-farming area and any terrorists living there would stick out like a sore thumb.