RELATED: Family friend mourns 21-year-old pregnant woman, baby killed in San Jose hit-and-run
Police say they arrested the suspect on Saturday, four days after the deadly crash at Blossom Hill Road and Winfield Boulevard.
According to investigators, the car driven by the suspect, a white Hyundai sedan, was stolen.
Two others in that car remain on the loose.
The woman killed has been identified as 21-year-old April Zoglauer.
Zoglauer was pronounced dead at a local hospital and doctors were originally able to save her baby by emergency surgery. But just 24 hours later, the baby died at the hospital.
MORE: Mother killed, twin boys injured by suspect in stolen car following East Bay pursuit, police say
A family friend set up a GoFund Me Page to help with expenses.