A backlog of cases has built up at the state police drug lab in Concord as the number and complexity of drug investigations is increasing.

Officials at the lab said that drugs are being tested nearly around the clock, but it's still an uphill battle. Lab director Tim Pifer said there are about 3,000 backlogged cases, and the number is growing.The lab takes in evidence from about 750 new drug cases each month, which is about 100 more than workers can safely process, Pifer said. Some, such as possession cases, will wait several months.

Read more and watch a video on the story here.