Some newspapers and TV stations have rules that they do not name suspects unless and until they are officially charged. I'm sure the press knows who they are.
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.