BOSTON — One is serving two life sentences after a 2013 racketeering conviction tied him to 11 murders and other gangland crimes in the 1970s and 1980s. The other has acknowledged taking part in the Boston Marathon bombing. The crimes shocked Boston, but with cameras banned in federal courts, ordinary Bostonians have been denied a chance to watch the ongoing trial of Dzhokhar Tsarnaev, as they were during the trial of James “Whitey” Bulger two years ago. Instead, they’ve had to rely on the …