The newborn girl found in a Turlock trash bin in November died of suffocation, the Stanislaus County district attorney's office said Thursday.
The coroner's report lists the cause of death for Maria Mae Betts as "asphyxiation by suffocation," Deputy District Attorney Annette Rees said.
Authorities arrested her mother, 19-year-old Jessica Mae Betts, on Nov. 20 and charged her with first-degree murder.
Betts told police she delivered a baby girl in the bathroom of her boyfriend's house in Turlock on Nov. 8, wrapped the newborn in a pair of purple sweat pants and a towel, and drove to Save Mart in her boyfriend's white Chevrolet, where she cried as her baby's breathing slowed and then stopped, according to search warrant documents.
The infant's body was in a white Target bag with its top tied closed, according to the man who found her. Jeff Merrow, 49, of Turlock said the girl's umbilical cord was attached when she was discovered in the afternoon. She was blue and didn't seem to be breathing, Merrow said.
Betts told detectives she didn't know how the newborn got into the Dumpster on Lander Avenue, less than a mile from where her boyfriend and his father live.
Jessica Betts' mother, Lillie Mae Betts, told Turlock police she found her daughter's diaries telling of a past pregnancy, the birth of a child and its "possible disposal" in 2007, according to the affidavit for a search warrant.
Rees said there have been no new charges filed against Jessica Betts but an investigation is ongoing.
Lillie Betts suspected her daughter was pregnant again and involved in abandoning a child after reading a newspaper story about a baby girl left in a Dumpster, the search warrant says.
She went to police less than two weeks later and her daughter was in custody by 3 p.m. that day, according to the search warrant affidavit.
DNA tests confirmed that the baby was Jessica Betts' daughter.
Jessica Betts has pleaded not guilty and faces a maximum sentence of life in prison if convicted. She remains in custody at the Public Safety Center in Modesto with bail of $1 million.
Betts will be back in court for a hearing Feb. 26.
Bee staff writer Merrill Balassone can be reached at email@example.com or 578-2337.