About 20 minutes before the shooting started at an El Paso Walmart, a rambling screed was posted to an online message board saying the massacre was in response to an "invasion" of Hispanics coming across the southern border, the AP reports. Titled "The Inconvenient Truth," it railed against the dangers of mass immigration and warned that Hispanics will eventually take over the economy and government. The writer argued that attacking "low-security" targets was a way to "fight to reclaim my country from destruction." Investigators increasingly believe these are the words of 21-year-old suspect Patrick Crusius, who surrendered shortly after Saturday's rampage, which killed 20 and wounded 26. More from the manifesto: