Sara Krueger and Ryan Scott Warner are scheduled to be arraigned Tuesday afternoon in a Napa County courtroom, prosecutors said. The couple was arrested Sunday after officers conducted a welfare check Saturday at Krueger's apartment and found the child's lifeless body in her bed, Napa police Lt. Debbie Peecook said.
Witnesses had seen Krueger and Warner leaving the apartment with some luggage a few hours earlier, police said.
On Sunday, someone spotted the couple at a restaurant near a Bay Area Rapid Transit station Sunday in the San Francisco Bay Area suburb of El Cerrito and alerted BART police, Peecook said Monday.
The couple was detained without incident at the El Cerrito station, about 30 miles south of Napa, BART police Lt. Gil Lopez said.
Krueger, 23 and Warner, 26, were questioned and booked on suspicion of murder with special circumstances and assault on a child resulting in death, all felonies, Peecook said. The couple, who has a history of drug use, could face more charges, she added.
It's unknown if the couple has retained an attorney.
The child, whose name has not been officially released, showed signs of having been sexually assaulted and blunt force trauma, investigators said. An autopsy was being conducted Monday, Peecook said.
Police have visited the couple's apartment numerous times in response to calls from neighbors, but no arrests had been made, Napa police Capt. Jeff Troendly said Monday.
Officers last visited the apartment on Thursday to conduct a welfare check on the girl, Troendly said. Everything appeared to be all right, he added.
On Sunday night, more than 50 people participated in a candlelight vigil outside the girl's apartment, where they left flowers and balloons, the Napa Valley Register reported (http://bit.ly/1ejqZQx).
John Krueger, Sara Krueger's father, embraced relatives and friends with tears in his eyes.
"This is the saddest part of any grandparent's life," he said. "The proudest moment of my life is gone forever, and there's nothing we can do or say that will bring her back."
The girl's biological father, who is serving time at San Quentin State Prison, was notified of her death.
The property manager at Krueger's apartment building told the Register that in recent months, police visited the mother's residence for several disturbances, including late-night noise, slamming doors and neighbors reporting possible physical abuse of the child.
Warner "moved in about 10 months ago, and it all went downhill from there," Elizabeth Chechourka said. Peecook told reporters that Warner and Krueger were linked to drugs, but did not give details, the Register reported.
"Management sent a letter to them about 2 1/2 weeks ago saying, 'The authorities know about you, and you need to shape up or you're gonna lose your housing,'" Chechourka said.
Napa police had made several welfare checks at Krueger's home, most recently last week, but none of the visits resulted in an arrest, Peecook said.
She said she didn't know whether Napa County Child Protective Services had visited the apartment in response to any neighbors' complaints.
A family friend who often baby-sat the girl was baffled by news of the girl's death and her mother's arrest.
"Never saw her raise a hand to the girl. It was like pulling teeth getting her to somewhat discipline her," Kindra Kunkel told reporters.
"This is not Sara; this is not the Sara I know," Kunkel said. "She fought so hard for her little girl."