Update: 5:50 p.m. - The toddlers have been found safe.
Updated at 5:19 p.m. with more details from police.
A St. Louis man killed his baby today and fled with two of his other young children, police say.
Diata Crockett, 34, was trying to shoot his wife but the bullet struck eight-month-old Reign Crockett instead, St. Louis police Chief Sam Dotson told reporters this afternoon.
The child was in the mother's arms at the time, Dotson said. An Amber Alert was issued for the boy's missing siblings, but it was canceled shortly before 6 p.m when the children were found safe.
"Violence against children makes you question humanity, so I'm having one of those moments today," the chief said.
Crockett, whose long criminal history includes assault and drug convictions, had argued with the mother in the Bellefontaine Neighbors section of north city, eventually pulling a gun and scaring her into the car, Dotson said.
The couple argued as they drove along I-270 with three of their six children.…