Police across US patrolling in pairs

US Police departments across the country are ordering officers to pair up after ambush attacks left eight officers dead in Texas and Louisiana, a precaution that could slow response times to low-level crimes and drive up overtime for already exhausted police. Los Angeles police assigned members of specialised crime-fighting units to back up officers responding to routine calls. Baltimore police began sending two squad cars to every call received. Dispatchers in Denver urged officers to travel in pairs indefinitely and "keep their head on a swivel" to protect themselves against potential threats. Los Angeles also ordered more of its helicopters to patrol the skies. Officers elsewhere were told to keep their guard up, especially around police stations. It was unclear when operations would return to normal.