A California mother has been arrested on suspicion of murder after her boyfriend came home and found their 4-month-old son dead.
Thi Nhat Ha Nguyen, 29, was arrested Dec. 12 after her boyfriend, Hung Nguyen found their young son, Nau, unresponsive with marks on his face at their home in Westminster.
"I came in and said, 'What's going on," Hung told KABC. "And she said, 'Go!' I came to get on the bed so I could touch my child. I see some marks ... and my son he can't move."
Hung told KTLA that when he asked his girlfriend what happened to their son, she wouldn't stop laughing. He called police, who tried to revive the baby. Nau was rushed to a hospital, where he was pronounced dead.
Police arrested Thi on suspicion of homicide, although the baby's official cause of death has yet to be determined. Police note the baby was found with traumatic injuries but did not provide further details.
"She loved him a lot," Hung told KABC. "I don't think she did that. But who else?"
Hung told KTLA his girlfriend had previously tried to take her own life when she was pregnant.
"She had a lot of stress in July when she was still pregnant and she tried to kill herself one time," he said. "She took 25 pills."
Police did not speculate on a potential motive, but said they are considering postpartum depression.
"That's always a factor and consideration when you find a young mother and a young child," Westminster Police Commander Cameron Knauerhaze said. "Certainly our investigators will evaluate that."
Almost 15 percent of new mothers will experience postpartum depression, according to the National Institute of Mental Health. Women who experience postpartum depression may have thoughts about harming themselves or their children.
Postpartum depression isn't caused by any specific factor, but rather a combination of hormonal and environmental changes mothers go through after giving birth, according to NIMH. A rapid drop in hormones post-pregnancy results in chemical changes in the brains of new mothers. Combined with the stress of caring for a newborn and chronic sleep deprivation, these changes can lead to postpartum depression.
Other symptoms of postpartum depression include feeling sad or crying for no reason, anxiety, moodiness, anger, withdrawing from social activities, suffering persistent aches and pains, doubting your ability to care for your baby and being unable to form an emotional bond with your baby.