There seem to have been conflated issues, with the somewhat surprising amount of money the terrorist couple had in the bank being somehow tied in with the "huge" cache of weapons (like...four?) and ammo (not much by my estimation). The rifles would have been something at or under $900 each these days. A thousand round case of 5.56mm ammo might go for about $300. Pistols @ $500 each or so. I won't speculate on the pipe bomb making supplies, but that's an historically low-tech/low-cost endeavor.
So it's like any other high-profile case. One bit of info is let out and the reporters grab it and mix it with three other bits, ten rumors they heard, what the supposed eye-witnesses are saying on the morning shows and AM radio call-in, etc.
Remember, few people who are ever interviewed about anything recognize much truth or factual reporting in the news piece that eventually airs.