CHICAGO -- As she left Latino Youth High School last month, 19-year-old Marlen Ochoa-Lopez had one quick errand to run before picking up her 3-year-old son from day care. It would be the last time she was seen alive.
Nine months pregnant, Ochoa-Lopez drove to a home on the Southwest Side where a woman she met through Facebook was offering a double stroller and maybe some baby clothes. Once inside, police say Ochoa-Lopez was strangled and her baby boy cut from her womb.
But the newborn had problems breathing and the woman who had lured Ochoa-Lopez to the home made a frantic 911 call saying the baby was "pale and blue." The baby was rushed to a hospital, where the teen's family says the boy is brain-dead but still hooked up to life support.
Ochoa-Lopez's body was dumped behind the home in the 4100 block of West 77th Place, where it was discovered early Wednesday -- nearly four weeks later -- after residents of the home were taken into custody, police said.
As police questioned the suspects Wednesday night, Ochoa-Lopez's 20-year-old husband stood outside the Cook County medical examiner's office and vowed justice for his young wife.
"Why did these people, why did these bad people do this? She did nothing to them," said Yovani Lopez, stretching his arm in back of him, toward the morgue. "She was a good person.
"We're going to have justice with those responsible," he added. "We're going to go hard after them. We won't let it go."
Police say they are questioning four people, including a 46-year-old woman who contacted Ochoa-Lopez through a Facebook group for mothers.
"We believe all of them played some role in this unspeakable act of violence," police spokesman Anthony Guglielmi said.
Following is a timeline of the case, pieced together from police, fire officials, the medical examiner's office, the family and neighbors from the home where Ochoa-Lopez was found.