Over the decades, tens of thousands of legal residents have been deported for relatively minor offenses. But under previous administrations, immigration authorities have often let low-level offenders off the hook, prioritizing the deportations of violent criminals. A memo from the Obama administration in 2011 directed immigration officials to look at a number of factors, such as familial relationships with U.S. citizens, criminal history, education and contributions to the community, in deciding whether arrests and prosecution are warranted, as The Post's Kristine Phillips reported.