When the co-worker went to check on Lockner, she found blood on the restroom floor, the Times reported. San Mateo County prosecutors said Lockner tried to blame a heavy period for the mess.
A second co-worker who checked on Lockner peered over the wall of Lockner's stall and saw the newborn face down in the toilet, prosecutors told the Times. The co-worker alleged that Lockner had her hand on the infant's back and that she heard the toilet flush.
Lockner begged her co-workers not to call police, but they dialed 911. First responders arrived and found the baby boy without breath or a pulse. He was resuscitated successfully.
San Mateo County District Attorney Steve Wagstaffe told The Mercury News earlier this year that the child was living with his father's aunt and meeting all his milestones.
It was not immediately clear if Lockner will be able to regain custody of her son, who is now 20 months old.
Prosecutors said Lockner previously gave birth at home about five years ago, the News said. There was nothing criminal about that birth.
Lockner told investigators she did not know she was pregnant with either child prior to giving birth. Her first child’s whereabouts were not made public.