Dec 2013: A student shoots up CO high school with a shotgun. Denver Post scrubs his self-described "socialist" beliefs.
Oct. 2013: Media retroactively blames right wing for JFK assassination. (Actually, LHO was a communist defector.)
April 2013: Tsarnaev bros bomb Boston Marathon. Media suggests RWNJ commemorating "Patriot's Day." (Actually, just more jihadist scum.)
Aug 2012: Floyd Lee Corkins shoots a security guard at the Family Research Council based on the Southern Poverty Law Center's "target list." Media: [crickets].
July 2012: James Holmes shoots up theater in Aurora, CO. Brian Ross suggests he's a TPer on live TV. (Just another unmedicated nutter.)
Jan 2011: Jared Lee Loughner shoots up campaign event of Rep. Giffords. Media: TP rhetoric is to blame. (An apolitical conspiracy theorist.)
Dec 2010: Clay Duke shoots at FL school board. Mike Malloy blames Glenn Beck. (Actually, Media Matters among his favorite sites.)
Sept 2010: James Lee takes hostages at Discovery Chan HQ. Media speculates: climate change denier? (An environmentalist who hates humans.)
August 2010: Amid GZM debate, Muslim cabbie stabbed in NYC. Media speculates it's a "rigth-wing nut job" (Actually, a lefty art student off his meds.)
May 2010: massive Times Square car bomb found. Bloomberg speculates it's someone upset about ACA. (Actually, plain vanilla jihadist scum.)
March 2010: John Patrick Bedell shot two Pentagon security. A right-wing extremist, media asked? (A registered Democrat and 9/11 Truther.)
Feb 2010: Amy Bishop shoots colleagues at University of Alabama faculty meeting. Gun-loving Tea Party suspected. (She was an Obama voter.)
Feb 2010: Joe Stack flies small plane into an IRS building. Anti-tax TP rhetoric blamed. (He quoted from the Communist Manifesto.)
Sept 2009: census-taker Bill Sparkman found hanged in rural Kentucky. Media speculated it was Tea Party. (He killed himself.)
Thanks to @gabrielmalor for the list.