A jury has convicted a 27-year-old man of involuntary manslaughter and assault on a child resulting in death for his role in the death of his girlfriend's 18-month-old son in 2014, San Mateo County prosecutors said.
Marco Antonio Alvarado-Cisneros was convicted Monday on the third day of jury deliberations following a trial on charges including murder of the toddler, Dante Nava, who died on Aug. 12, 2014. The jury found him not guilty of murder, but convicted him on the lesser charge of involuntary manslaughter.
The death happened when Alvarado-Cisneros and his girlfriend were living together in an apartment just outside of Redwood City and the girlfriend went off to work, leaving the child in his care, prosecutors said.
Hours later, Alvarado-Cisneros called 911 to report that Dante was unconscious and not breathing, and may have had a seizure. He told paramedics that the child had been awake, but when Alvarado-Cisneros turned away for a moment, the boy may have fallen off the bed.
Dante was pronounced dead shortly afterward, and an autopsy revealed numerous injuries, including a massive subdural hematoma, hemorrhages to his retinas, bruises on his body and several adult bite marks, prosecutors said.
However, Alvarado-Cisneros' girlfriend was not cooperative with the investigation and he was not initially charged in the child's death.
The pair continued living together for months afterward and had a child together, but the relationship was tumultuous and deputies responded to numerous domestic violence calls at the home, prosecutors said.
The girlfriend finally came forward in September 2015 to report that Alvarado-Cisneros had repeatedly abused, kidnapped and robbed her, and the ensuing investigation led to his being charged in the toddler's death.
He will return to court for sentencing on June 4, and faces 25 years in prison for the charge of assault on a child causing death and four years for involuntary manslaughter, prosecutors said.
Alvarado-Cisneros' defense attorney was not immediately available for comment on the case.