KOKOMO, Ind. -- The boyfriend of a Kokomo woman whose 11-month-old son died from a blow to the head was arrested Wednesday in the boy's death.

Derrick A. Fox, 28, took Malaki Lindley to a Kokomo hospital early Sunday unconscious and unresponsive, said Kokomo police Lt. Don Whitehead.

An autopsy later determined that the boy had died from blunt force trauma to the head.

Fox was taken into custody on Wednesday and preliminarily charged with neglect of a dependent resulting in death, Whitehead said.

Police said Fox was caring for Malaki Lindley while his mother, Katie Lindley, was at work.

The boy's aunt told 6News' Jennifer Carmack on Tuesday that she couldn't understand how anyone could hurt her nephew.

"This poor little baby; it's shocking," Whitney Lindley said. "We're still dealing with the fact that he's gone. He's gone forever."

Malaki Lindley would have turned 1 year old on Friday.

Fox was being held at the Howard County Jail with no bond.