(CNN) -- Police looking for a man, woman and four boys reported missing in California turned up the body of a woman late Wednesday in the trunk of what appears to be their family car.
Daniel and Erica Perez own two black vehicles. In one, a Toyota Camry sedan, Montebello police say they think father Daniel is driving the couple's young sons, not answering police calls to get in touch with them. An Amber Alert has been issued for the sons, Tristin, Jordan, Jaden and Alex.
Police would not say that the body found is that of Erica Perez. The coroner has not identified the dead woman yet, said police spokesman Capt. Luis Lopez.
But she was found in a car perfectly matching the family's other vehicle, a black Honda with the same license plate number, CNN affiliate KCAL reported.
Police towed it away from where it was abandoned, at a hospital half a mile from the Perezes' deserted home.
Family members told police that the Perezes' marriage was rocky and marred by domestic violence.
Police and Erica Perez's family now share a top priority: bringing the children to safety. Lopez asked the public to report any sighting.
The couple has a fifth son, who is staying with his grandmother.
Erica's sister, Pam Valdez, took journalists' questions at a news conference late Wednesday but quickly broke down into sobs and pleaded directly with the children's father.
"Please, Danny, bring the kids back. Just drop them off at a fire station somewhere," she begged. "Don't hurt them please. They're innocent."
CNN's Tina Burnside contributed to this report.
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