It's more than just Jared Loughner
Michelle Malkin has a nice rundown of the previous adventures of the Blame Righty Mob, which fell suddenly and universally silent when it was time to Blame Lefty for Chris Dorner. Tucson shooter Jared Loughner was but the highest-profile killer they tried to pin on the Right:
Question: How many times over the past four years have exploitative liberal journalists and Democratic leaders rushed to pin random acts of violence on the tea party, Republicans, Fox News and conservative talk radio?
Answer: Nearly a dozen times, including the 2009 massacre of three Pittsburgh police officers (which lib journos falsely blamed on Fox News, Glenn Beck and the “heated, apocalyptic rhetoric of the anti-Obama forces”); the 2009 suicide insurance scam/murder hoax of Kentucky census worker Bill Sparkman (which New York magazine falsely blamed on Rush Limbaugh, “conservative media personalities, websites and even members of Congress”); the 2009 Holocaust museum shooting (which MSNBC commentator Joan Walsh blamed on Limbaugh, Bill O’Reilly and yours truly); the 2010 Times Square jihad bomb plot (which Mayor Michael Bloomberg falsely blamed on tea party activists protesting Obamacare); and the 2011 Tucson massacre, which liberals continue to blame on former GOP vice presidential candidate Sarah Palin.
And it's too cute to watch eight or 10 pages getting conveniently deleted from media reproductions of the Dorner manifesto when they were falsely ginning up links to conservatives or the Tea Party within hours of these other events. The Left-media rests comfortably in the knowledge they'll never have to answer questions about these editorial decisions; nobody gets to ask them questions. It would be fascinating to hear what the more aggressive Dorner memory-hole attendants came up with to justify concealing his political preferences, if they could be somehow compelled to explain themselves in public.