A 23-year-old mother is accused of intentionally drowning her 2-month-old son in a hotel bathtub, according to Fresno, Calif., police.
Espinosa had no criminal record or history of mental illness, and had never had any issues with Child Protective Services before the arrest, KFSN reported.
"What's really unique in this situation isn't just that an innocent child died, but that a child died at the hands of his own mother," Fresno Police Department Deputy Chief Robert Nevarez said in an interview with KFSN.
Calls from ABCNews.com to the Fresno Police Department were not immediately returned today.
The woman came to police attention around 4 a.m. Saturday, when she was spotted driving erratically on Highway 41. She allegedly left the scene of one accident, was chased along the highway and was detained after getting in another crash.
When California Highway Patrol officers questioned her, she allegedly told them about her son.
"The CHP interviewed miss Espinosa and at some point, she told them she had three children at a nearby hotel, the Economy Inn at 4290 North Blackstone and that she had drowned her 2-month-old," Nevarez said.
CHP investigators went to the motel and found the baby, not breathing. They attempted to revive the child, but could not and he was pronounced dead at around 7 a.m.
An autopsy was scheduled today to determine the cause of death and to positively identify the child.
There were two other children in the room, but neither was hurt and police said they did not believe she had tried to hurt either one. Police had not released the names, ages or sex of the other two children, who were taken into the care of Child Protective Services.
"Oh, I can't believe it. It's scary. It's so sad. A baby," Molly Morin, who works at the Economy Inn, told KFSN.
She told the Fresno Bee that she was there when Espinosa check in, and noticed nothing unusual about the woman. She said the little boy was in a stroller while she was checking in, and when the baby started to cry she went to check on him.
"She seemed fairly normal, but it seemed like she might have been going through some problems or something," Morin said.
David Weaver, who was staying at the Economy Inn, told KFSN he saw members of the coroner's office bring the baby out of the room.
"Well, it was obviously a small child," Weaver said. "It's heartbreaking to see the little kid come out like that whether it was natural, it's heartbreaking. If it's violent, it's sad."
Espinosa was treated at hospital for internal bleading caused by the two car crashes and released after her arrest.
She was being held in the Fresno County Jail on charges of suspicion of murder and willful cruelty to a child, according to information on the Fresno County Sheriff Department's inmate database.
Police were also awaiting the results of tests to determine whether she was drunk or under the influence of drugs when she was pulled over.