Boston police camera footage proving useful, but only on a limited basis

In September, prosecutors used footage from a Boston police officer’s body camera to convince a judge that a defendant was dangerous and should be held in custody.

That same month, the recording of an arrest in West Roxbury refuted claims of officer mistreatment and showed signs that the suspect had mental health issues, leading prosecutors to recommend treatment.

Since June, when officers across Boston began wearing body cameras after years of resistance, the chest-mounted devices have provided valuable information for internal investigations and prosecutions, law enforcement officials said. But in a number of high-profile cases, the absence of footage has been glaring, spurring frustration that the department has not moved quickly enough to make body cameras more widespread.