US couple who pointed guns at Black Lives Matter protesters outside their mansion could face charges

A couple who pulled guns on Black Lives Matter protesters outside their Missouri mansion may now face charges after an investigation was launched.

Lawyers Mark and Patricia McCloskey, 63 and 61, were captured pointing an assault rifle and a pistol at demonstrators, who gathered on their private street in St Louis and fired insults at them.

Local police initially said the pair would not be punished for their actions, but the city's prosecutor, Circuit Attorney Kimberly Garnder, says she's now working with police to investigate them.

"I am alarmed at the events that occurred over the weekend, where peaceful protesters were met by guns and a violent assault," she said at a press conference on Monday night (local time).

"We must protect the right to peacefully protest, and any attempt to chill it through intimidation or threat of deadly force will not be tolerated. Since learning of these events over this weekend, I've worked with the public and the police to investigate these tragic events."

It's not known what charges the McCloskeys would face.

Since footage and photos of the McCloskeys holding the weapons went viral, the pair have defended their threats and deny they were race-related.

"My clients, as melanin-deficient human beings, are completely respectful of the message Black Lives Matter needs to get out, especially to whites," their lawyer Albert Watkins said.

He told The St Louis Post their actions were lawful and came about as a result of their "fear and apprehension, the genesis of which was not race-related".

It was widely reported protesters destroyed the McCloskeys' iron gate to get near their property, and that their targeting of the couple was what caused them to brandish firearms.

However the protesters dispute these claims, with footage from the incident appearing to show their gate intact and one demonstrator saying they didn't even see the McCloskeys until they came out of their mansion.