A Montgomery County man, sentenced to two life sentences for rape Thursday, posed as a police officer and preyed on the fears of illegal immigrants, revealing what State’s Attorney John McCarthy called a growing trend among criminals.

John Robert Lay, 51, whose criminal history stretches back more than 30 years, is already serving time in a Virginia prison for sexually assaulting an illegal Hispanic woman in Fairfax County in 2001. He was convicted of that crime in 2006.