Ramirez is accused of posing as a nurse who came into the room of the baby's mother and told her to take a shower before a doctor came to examine her, Nightengale said.
Once the baby's mother was out of the room, Ramirez allegedly put the newborn in a purple tie-dyed tote bag and tried to carry her out of the ward.
"An alarm went off when the baby crossed an imaginary line" in the hospital that set off a sensor, Nightengale said.
Many hospital wards have security systems where patients, such as newborns or those with Alzheimer's disease, are tagged with an electronic sensor — usually in a bracelet or anklet — that sets off an alarm when the patient leaves a certain perimeter.
Authorities would not say what kind of system the Garden Grove hospital uses.
Nightengale added that the baby was only in the bag for a short period of time. She wasn't harmed and is back in the care of her mother
Nightengale credits an alert employee and hospital policies for stopping Ramirez and saving the baby.
"The hospital staff reacted as they should," said Nightengale.
Investigators later concluded that Ramirez was the woman who walked into a hospital in Anaheim last week and asked several questions of a pregnant woman, Nightengale told KCAL-TV Monday night. The questions raised suspicions and the pregnant woman told authorities, prompting police to circulate a flier with Ramirez's picture on it, Nightengale said.
He said investigators have found no history of mental illness for Ramirez.