By Joel R. McConvey

Transit officials in Los Angeles have declared a public safety emergency over the stabbing of a 66-year-old woman in the city's Metro transit system, and are planning to deploy facial recognition tools to help identify repeat offenders and deter violent crime, according to reports from the Los Angeles Times and Los Angeles Daily News.

Beatings, stabbings and other violent incidents have been rising on L.A.'s public buses and trains, including four attacks in April. The perpetrator of the stabbing attack that killed Mirna Soza Arauz had a prior ban from the transit system for violent altercations. But Metro says its officers had no way of knowing that a dangerous individual was riding the train. Had facial recognition systems been in place, they might have made the match.