The U.S. Department of Justice is no longer investigating SandRidge Energy for antitrust violations, according to a Securities and Exchange Commission filing . "On April 14, 2016, the U.S. Department of Justice notified the Company that it is no longer a subject or target of the previously reported grand jury investigation of possible violations of antitrust laws in the purchase or lease of land, oil, or natural gas rights from 2012 and previous years," the filing, which was released Friday, read.