Retired lieutenant arrested in fatal shooting of D.C. library officer during training

A retired police lieutenant has been arrested after police say he fatally shot a fellow law enforcement officer Thursday during a training exercise at a Washington D.C. library.

Jesse Porter was at the end of a training exercise at a library in the district's Anacostia neighborhood Thursday afternoon when he fired a weapon that struck 25-year-old Maurica Manyan, Metropolitan Police Chief Robert Contee said Friday. The library officer was then rushed to a local hospital where he was later pronounced dead.

Porter was arrested on an involuntary manslaughter charge after police consulted with the U.S. attorney's office in Washington. He remained in custody Friday, and it was not immediately clear if he had an attorney who could comment on his behalf.