SAN FRANCISCO — In a federal gang murder case last year, criminal defense attorney John Philipsborn tried to get U.S. District Judge Maxine Chesney to hold a hearing on the integrity of drug evidence coming out of the San Francisco crime lab. He didn’t get far.

But now, Philipsborn and his client, Dennis Cyrus Jr., are getting a real chance to raise drug lab concerns with the court — nearly a year after a federal jury convicted Cyrus but before he’s sentenced.