The shooting occurred nearly a year ago on June 2 while Vallejo police officers were responding to a report of vandalism at a Walgreens and saw the 22-year-old Monterrosa retreating from the store. Police said the officer who fatally shot Monterrosa mistook a hammer in his sweatshirt pocket for a gun.
"Today I am announcing the Department of Justice will be taking on the review of the case of the tragic shooting that led to the death of Sean Monterrosa," Bonta said.
Bonta promises a thorough and unbiased review, adding it is time for the community and Monterrosa's family get the action they have been demanding.
"Without accountability, there is no justice," Bonta said. "It's past time Sean Monterrosa's family, the community, and the people of Vallejo get some answers."
Solano County District Attorney Krishna Abrams has declined to take on the case, saying an outside review is needed to restore public trust. But Bonta said there is no excuse for her inaction.
"The Solano County DA has recused herself when there was no basis to do so," Bonta said. "There is no actual conflict under the law."
Abrams late Thursday released a statement in response to the attorney general.
"Attorney General Bonta within weeks of being appointed is already playing politics with one of the most critical and divisive issues in our communities today - officer involved fatalities," Abrams said in a statement. "It is beyond disappointing that we can't trust the statements of the Attorney General."
Monterrosa's family has since filed a civil rights lawsuit against the city and police officer, and also put up a billboard near the Vallejo Police Department. His sisters said they are encouraged the state's top cop is stepping in.
"Wherever the facts and law lead, that's where we will go," Bonta said.