Shooting likely to reignite debate as gun violence claims 33,000 lives a year

SAN BERNARDINO, California - A man walked into a school in southern California on Monday and shot dead his estranged wife in front of her students, killing an eight-year-old boy in the crossfire before turning his gun on himself.

Police said local resident Cedric Anderson had checked into the office as a visitor after entering the campus in the city of San Bernardino and going to a classroom, where he opened fire on Karen Elaine Smith, 53, as she was teaching.

Officers said Anderson, also 53, had only targeted Smith but two students were caught in the crossfire and one of them, Jonathan Martinez, died later in hospital.

"This does appear to have been a murder-suicide with both male adult and female adult victim succumbing to injuries, with the male succumbing to a self-inflicted gunshot wound," said Lieutenant Mike Madden of the San Bernardino Police Department.

Police said initially the two wounded students had been listed as critical but later confirmed Martinez's death.

Students at North Park Elementary School - which has around 500 students between kindergarten and sixth grade - were transported to a nearby campus, where they were "being well cared for, having snacks, playing games and watching a Disney movie", the police department tweeted.

San Bernardino was the scene of horrific violence when Syed Rizwan Farook and his wife Tashfeen Malik gunned down 14 people in December 2015 before being shot dead by police.

Massacre

At the time, before the Pulse nightclub shooting in Orlando, it was the deadliest attack on US soil since Sept 11, 2001.

Pakistani-born Malik - who met her future US-born husband on a Muslim dating website and married him in Saudi Arabia - had pledged allegiance to the Islamic State group on Facebook and was instrumental in radicalizing him.

Monday's shooting will likely reignite the debate on gun violence in the US, where attempts to put in place tougher gun control measures have failed, despite a series of mass killings.

In one of the most notorious school shootings in modern US history, 20 children and six staff were massacred in 2012 at Sandy Hook Elementary in Newtown, Connecticut.

In June, 49 people were killed in a shooting rampage at Pulse, a nightclub in Orlando.

"School campuses are sacred spaces where children should be free to learn, play and grow without threat of violence," Los Angeles Mayor Eric Garcetti said in a statement.

"Today's shooting ... is a reminder that deadly weapons can shatter that sense of security, mercilessly and without warning - leaving parents and educators struggling to address the questions, fears and anxieties that gun violence creates for our young people."

More than 33,000 US residents die every year from guns, including suicides, a rate far higher than in other Western countries.