Once authorities arrived at the couple's home in the 5100 block of McCallum Avenue about 5:40 p.m., the baby was unresponsive.
She was rushed to St. Francis Medical Center in Lynwood, but doctors could not save her. She died of blunt force trauma.
Neighbors said they were shocked over the news.
"It's a young couple, kind of just like ourselves. It's just kind of scary especially since it's like just three houses away from us. So it just kind of makes me feel uncomfortable," said Jazlin Romero, a neighbor.
Deras is described as a male Hispanic with long, black, curly hair, a dragon tattoo on his right shoulder and skulls on his right upper back. He stands about 5 feet 8 inches and weighs 160 pounds.
Authorities are also looking for a black, four-door 2008 Nissan Sentra with California license plate 6FYB170. Anyone with information is asked to call Crimestoppers at 1-800-222-TIPS or 1-800-222-8477.