Surveillance cameras caught the dramatic moment when Sammie Wallace grabbed the child while her mother, Alicia Keating, had her back momentarily turned.
As Keating screamed for Wallace, 37, to return her child, law enforcement arrived and cleared the store.
"He had a weapon in his hand," said Midwest City, Okla., Assistant Police Chief Sid Porter. "A knife-type weapon holding up against the child, threatening the child's life."
Porter said Wallace was uncooperative during more than 30 minutes of negotiations. Then the situation began to deteriorate, with Wallace making strange demands and counting down from 60.
An officer distracted Wallace while another, Capt. David Huff, moved and fired a single shot at his head, killing him.
“Obviously, our goal was to talk him down to get him to release the child,” said Midwest City Police Chief Brandon Clabes. “Unfortunately, we weren’t successful but we were successful in saving this child and the fact is that Capt. Huff’s actions were extremely heroic and he waited till the very last moment.”
"I mean, we waited until the last second to use deadly force," Clabes said. "No one wants to take a life, especially in the line of duty."
Notable deaths of 2014 [PHOTOS]