SAN FRANCISCO -- The city of San Francisco is partially responsible for the fatal shooting of a father and his two sons by a gang member who was shielded from deportation by the city's "extreme" immigration sanctuary policy, the slain family's attorney said in a claim filed Friday.

Tony Bologna, 48, and his two sons, 20-year-old Michael and 16-year-old Matthew, were gunned down at an intersection in June. Police arrested Edwin Ramos, a native of El Salvador, who they say mistook the Bolognas for rival gang members.

Ramos has been charged with three counts of murder and is awaiting trial. He has pleaded not guilty.

The claim states that the city knew Ramos was a member of Mara Salvatrucha, or MS-13, with a violent past, but failed to report him as required by federal law to Immigration and Customs Enforcement officials.

The claim alleges the city knew Ramos "would likely murder men simply because they appeared to be Latino or African American."

"When a city is violating federal law and that violation of law leads to horrific consequences like this, then the city has clearly acted in a negligent manner," said one of the Bologna's attorneys, Kris Kobach, an immigration law professor at University of Missouri, Kansas City School of Law.

Kobach, who also served as former U.S. Attorney General John Ashcroft's chief adviser on immigration law and border security, said San Francisco's "extreme" sanctuary policy for illegal immigrants essentially bars police from contacting federal authorities when they arrest an illegal immigrant.

Ramos, 21, had been arrested as a juvenile for assault and attempted robbery, but was not deported because the city's juvenile justice system did not report him to federal immigration officials.

Matt Dorsey, a spokesman for City Attorney Dennis Herrera, said the office had not yet reviewed the claim, so would not comment.

The city has 45 days to respond to the wrongful death claim, which is a precursor to a lawsuit.

Mayor Gavin Newsom has called the city's policy "misguided" and "costly" for the city, and has said San Francisco will no longer shield young offenders who are illegal immigrants from federal officials.