The Minnesota man who killed two police officers and a firefighter-paramedic on Sunday had a criminal record going back nearly 20 years and was barred for life from owning firearms, authorities say. The gunman who opened fire on first responders in the Minneapolis suburb of Burnsville was identified Monday as Shannon Cortez Gooden, 38. Authorities said he took his own life after the Sunday morning standoff, the Star Tribune reports. Fox 9 reports that according to court documents, Gooden was convicted of disorderly conduct in late 2004 and arrested for disorderly conduct and domestic assault i…