When the gunman in the shootings of two Minnesota lawmakers approached their homes early on Saturday morning, he was armed with not just a handgun but also a wealth of other gear: a black tactical vest, a badge, a flashlight, a Taser. He arrived in a black S.U.V. with flashing police lights.

Prosecutors say the man charged with killing one Minnesota lawmaker and wounding another had dozens of apparent targets, including officials in at least three other states.