"It was like a real horror movie. It was Friday the 13th," he said. "When I saw my kid, how I saw my kid, that's when I knew what was going on."
On Friday night, Williams told police that she left the kids with a relative around noon and returned home late in the evening to find the children dead. Police say that's not true.
Jose learned Penn was one of two people Williams called that night.
Police said their brother saw his mother kill the boys.
Penn first met with Jose at a vigil with friends and family Saturday night. He told Jose that the last time he saw his two toddlers was last month.
"Ja’karter, Keyante, my world, my everything. I’m lost," he said.
Neighbors expressed their grief and disbelief at the vigil. They told Jose that the apartment "smelled like death" – a smell investigators say indicates the bodies may have been inside for a few days.
"How does a 1-year-old and a 2-year-old get in the stove?" said Neesha Smith.
Williams' mother, Breanda, told Jose that her daughter has struggled with mental health issues her whole life.
"I just came from the jail," she said. "I also let them know to put her on suicide watch because she’s gonna kill herself."
Lamora's sister, Tabitha Hollingsworth, believes that the deaths could have been prevented.
"This was something we saw that could possibly happen. She's had issues from a baby. Issues my mom tried to address with the state of Georgia," Hollingsworth said.
Williams is expected to make her first appearance in court Monday.