The Beltway Sniper was a Muslim but his killing spree was more akin to a classic loner serial killer. Here's a post from 2002 on that issue-
So, we have a merger of two theories, the Islamic terrorist and the home-grown nut-case. It looks like we have an Islamic home-grown nut-case....How much of JAM's motivation [is] Islamic and how much just good old-fashion rage against the system?
The same could be said of the Moore, OK beheadder. That is a mash-up of a classic "goin' postal" fired worker firing on his former co-workers and a jihadi-style beheading of a captured infidel.
The shooter was a Muslim convert, but he grew up in an era where workplace shootings by former workers are a somewhat regular occurrence. One case in Michigan a few years back had a beserker kill an pro-life protestor before going to his workplace, but we weren't blaming Planned Parenthood for setting him off.
When folks like the president (or Dubya back in the day) mention Islam as "a religion of peace", they don't mention that the peace in question is submitting to God and his teaching and the more radical folks will make you do that by force. It's a bit like Ming's "All creatures shall make merry... under pain of death" from Flash Gordon; not all that peaceful, especially if it's played out by someone who is frustrated and violent to begin with.
Contrary to Rick Perry's plea, this is one that the president can opt to pass on. He wouldn't say anything helpful or do anything helpful, nor would a conservative president do much that would make a difference.