The alert was issued at 10:30 a.m. Wednesday after 29-year-old David Olteanu allegedly kidnapped his son Alexsandr Olteanu.
David Olteanu allegedly sexually assaulted his estranged wife in Sacramento on Wednesday before taking their son and threatening to flee the country.
The Sacramento County Sheriff's Department then issued its first-ever Amber Alert and notified Interpol, sheriff's spokeswoman Sharon Chow said.
At about 8:30 a.m. today, Interpol located the father and son in Bucharest, Romania.