Police kill man who threatened US authorities

NEW YORK - A man who threatened on social media to kill police was shot dead by them near Philadelphia on Tuesday when he tried to run them down in his car, police said.

Upper Darby police superintendent Michael Chitwood said the suspect, a white man aged 52, "threatened to kill police, threatened to kill FBI agents" in videos posted on YouTube.

When police stopped the suspect's vehicle, "he put the car in reverse and tried to run over the Clifton police chief, smashing his SUV," Chitwood said.

Five of the officers then opened fire on the suspect, he said.

"They shot and killed him," Chitwood said. "He was using his vehicle as a weapon. They did what they had to do."

The man was identified as Joseph Pacini on Philly.com. Police did not immediately confirm his name.

In recent months, demonstrators have taken to the streets across the United States to protest what they say is disproportionate police violence against unarmed African Americans, including the July choking death of Eric Garner in New York and the August fatal shooting of Michael Brown in Ferguson, Missouri.

Grand juries probing both those cases declined to charge the officers involved.