Commencement speakers have been announced for two Lowell colleges, with the honored guests coming from the worlds of politics and law. US Interior Secretary Ken Salazar will deliver the address to the class of 2012 at University of Massachusetts Lowell’s ceremony on May 26 at the Tsongas Center. Known as a champion for conservation and protector of the environment, Salazar will be speaking before almost 2,700 undergraduate students. At Middlesex Community College, approximately 1,150 members of the graduating class will hear speaker Alex E. Ferrer at their commencement ceremony on May 24 in Lowell Memorial Auditorium. Best known as the host of television’s “Judge Alex,” Ferrer is a former police officer, attorney, and Florida circuit court judge.