Baton Rouge Police Department

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.

Authorities sought to learn more on Monday about a decorated ex-US Marine sergeant who killed three police officers in Baton Rouge, Louisiana, some two weeks after police there shot dead a black man, sparking nationwide protests including one shattered by the massacre of five Dallas policemen.

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.

Authorities sought to learn more on Monday about a decorated ex-US Marine sergeant who killed three police officers in Baton Rouge, Louisiana, some two weeks after police there shot dead a black man, sparking nationwide protests including one shattered by the massacre of five Dallas policemen.