A 29-year-old Westminster woman was behind bars Wednesday on suspicion of killing her 4-month-old son.
Thi Nhat Ha Nguyen, who lived with her boyfriend in a rented room in a home in the 15000 block of Coronado Street, was booked on suspicion of murder, according to Westminster police Cmdr. Cameron Knauerhaze.
Police were called just before 11 p.m. Tuesday by Nguyen's boyfriend, who said the suspect was acting "strangely" and their son was unresponsive and not breathing, Knauerhaze said.
Knauerhaze said the infant had unspecified traumatic injuries. The cause of the baby's death was not released.
The couple have no other children, police said.
Nguyen's boyfriend -- Hung Nguyen -- said last night the two had a fight. He says she ripped family photos off the wall and she was incoherent.
He told NBC4 his girlfriend had issues with depression.
"My son, he didn't move. And I called 911," he said.
Fighting back tears, he said his girlfriend loved their son.
"I don't think she did that," he said. "But who else?"
Neighbors and police said multiple families live in the home.
Police say Thi Nguyen's mental health will be evaluated while she's in custody.
NBC4's Vikki Vargas contributed to this report.