The father of two infant boys who were killed Friday night in southwest Atlanta is holding tight to his only remaining son, and his namesake.

"It is horrific,” said Jameel Penn. “Somebody leave a child there for that amount of time, or however it was, something ain't clicking right in your brain."

When police arrived at the Howell Place apartment, they discovered the children and saw burn marks on their bodies, possibly from a stove.

Williams, who will make her first court appearance on Monday, told police she had left the children with a cousin around noon on Friday and returned around 11:30 pm, discovering the caregiver gone and the children dead, an account police now dispute.

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There was a third child -- a 3-year-old boy, Jameel Penn Jr. -- at the apartment, who was not injured.

Penn said he was separated from his children's mother, and would see them on weekends. He said Williams called him Friday night, “and she is like, they’re dead. And I’m like, who’s dead?”

Moments later, Williams video-called Penn from inside the apartment. Penn said the scene was so gruesome, he can’t describe what he saw.

"Every time I close my eyes from now on, that is what I'm going to see," Penn said.

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Penn said he needs to focus on Jameel Jr. "Whatever he needs, whatever they need, I'm here," he said. "I can't forgive her. I don't know what to feel. I'm lost."

Tangye Penn, the boys’ paternal grandmother, is trying to understand how she lost two grandchildren.

"I don't see how any mother can sit there and harm their own child,” she said. “I really don't. Something got to be wrong with that person."