BROCKTON – A Brockton man has been sentenced to state prison after he was convicted on drug charges, Plymouth County District Attorney Timothy Cruz has announced. On Friday, Brockton Superior Court Judge Robert Gordon sentenced 31-year-old Derek Depina, to serve 6 1⁄2 to 8 years in state prison, to be followed by two years of probation from and after. The Commonwealth had requested that Depina serve 9-10 years.