Garrett Foster, 28, was shot and killed by someone in a car on Saturday while attending a protest in downtown Austin. Earlier in the evening, he was interviewed on a livestream while wearing an AK-47 across his chest.

Here is what else we know about the incident so far.

What do we know about Garrett Foster?

Foster had attended the ongoing protests regularly with his fiancée Whitney Mitchell, a quadruple-amputee, with whom he purchased a home in Austin two years ago, his mother, Sheila, told Good Morning America.

Mitchell's mother, Patricia Kirven, organized a GoFundMe to pay for Foster's funeral and burial costs. It raised more than $107,000.

"He fought against injustice, served in the military and was fiercely protective of his fiancée," Kirven wrote on the fundraising page. "They fell in love at 17 and were never apart."

Foster left the military to take care of Mitchell when she became sick with an unknown illness, which led to her amputations, Kirven told the Dallas Morning News. Foster had served as her full-time caretaker for nearly a decade.

Was he armed?

Foster was carrying an AK-47 at the protest.

Earlier in the evening, he spoke about the weapon to an independent journalist named Hiram Gilberto Garcia, who has been broadcasting live footage from the Austin protests. "They don't let us march in the streets anymore, so I got to practice some of our rights," Foster said in the interview, which was streamed on Periscope.

Austin Police Association President Ken Casaday tweeted a link to Garcia's video interview with Foster on Sunday. "This is the guy that lost his life last night," he wrote. "He was looking for confrontation and he found it."

Austin Police Chief Brian Manley said at a press conference on Sunday that the driver who shot and killed Foster told dispatchers that Foster approached his window and pointed a rifle at him.

But some witnesses dispute this account. James Sasinowski told CNN that the driver aggressively drove into the crowd of protestors and incited the violence..

What is the status of the investigation?

APD is actively investigating Foster's death, Manley said on Sunday, including reviewing available video, photos and witness statements. The Travis County Medical Examiner's office will conduct an autopsy.

Texas has a fairly broad stand-your-ground law, which doesn't require individuals to retreat when defending their home or other property.

Who organized the protest?

The Mike Ramos Brigade has organized regular protests against police violence and white supremacy in Austin.

In recent tweets, the brigade has referred to Foster as a "comrade" and "one of our own."

The group's members have not identified themselves, but APD confirmed last month that there is crossover between the brigade and another controversial local group called Defend Our Hoodz, which organized a rent strike and May Day protests earlier this year.

Mike Ramos was shot and killed by Austin police in April. His mother, Brenda, has said her family is not associated with the Mike Ramos Brigade.

What are local officials saying about Foster?

Austin Mayor Steve Adler tweeted on Sunday, "This is horrible as is all gun violence. There are too many guns."

Council Member Natasha Harper-Madison criticized the police response to Foster's death, including a Sunday press conference in which Manley spoke about rising violent crime in Austin and staffing shortages.

Council is in the middle of budget deliberations about whether to cut APD funding and staffing. Last week, hundreds of residents called into a meeting to urge council to cut more than the $11 million currently proposed.

"Whether we halve APD's budget or double it, nothing will bring back Garrett Foster," she wrote in a Facebook post on Monday, "and using a press conference about his death as a platform for political purposes is beneath contempt."