St. Louis Police officers guard the entrance to the Cathedral Basilica before Midnight Mass as protesters held a candlelight vigil on Wednesday, Dec. 24, 2014, in St. Louis. (AP Photo/St. Louis Post-Dispatch, Robert Cohen)

City officials in Berkeley, Mo. said on Tuesday that several witnesses have told police that 18-year-old Antonio Martin drew a gun and pointed it at an officer before he was shot and killed by that officer last week and provided new details about the encounter meant to undermine vocal protesters who have raised pointed questions about the shooting.

The Dec. 23 shooting, which occurred just 5 miles from where Michael Brown was killed in August, sparked protests and at-times violent clashes between police and residents last week, which left several officers injured and a gas station across the street partially vandalized.

“Mr. Martin was armed, Mr. Martin did attempt to fire when he pulled a weapon on the officer,” said Berkeley Police Chief Frank McCall, who added that several witnesses including the man who is seen walking with Martin moments before the shooting have confirmed that Martin drew a weapon on the officer before being shot.

The shooting sparked renewed protests in Greater St. Louis, where demonstrations have occurred almost nightly for the four months since Brown was shot and killed after an altercation with a white Ferguson police officer. That fatal shooting – and the grand jury decision to not indict officer Darren Wilson – was one of the driving forces behind the “Black Lives Matter” protests against police shootings that have sprouted in more than a dozen cities.

But top officials in Berkeley have insisted that the shooting of Martin should not be lumped together with that of Brown and the deaths of Eric Garner in New York and Tamir Rice and John Crawford in Ohio – all black men who were unarmed when they were killed by white officers – because Martin allegedly pulled a weapon on the officer.

Police in Berkeley have released several partial video clips that appear to show Martin approaching the officer, then walking away before lifting his arm. In a second video clip, the officer can be seen scurrying backward and falling down – his weapon discharging – before he ran for cover.

Mayor Theodore Hoskins said that groups that continue to protest the shooting have no “objective,” and said that demonstrations that attempt to “disrupt” the city such as one on Monday night that closed a local freeway, will not be tolerated.

According to police, they first received a call about shoplifting at a Mobil gas station at 11:11 p.m., with an officer arriving on the scene and confronting Martin – who police say matched the description of the suspected shoplifter – at 11:14.

One minute later, the officer radioed that shots had been fired.

McCall could not provide any details of the alleged theft, referring questions about what Martin allegedly stole to St. Louis County Police. He also speculated that Martin’s gun did not fire at the officer because the safety was on – but said that he had not directly examined the weapon.

A common criticism and question from protest groups has concerned whether Martin was given medical attention after being shot. Within 20 minutes of the shooting, many of the protesters who have demonstrated in Ferguson had shown up at the scene of the shooting – including at least one who provided livestream video footage. Many online have questioned why no paramedics were seen tending to Martin by the protesters who arrived.

However, city officials insisted that paramedics arrived at the scene of the shooting at 11:21 p.m. – approximately six minutes after the shooting – and had declared Martin dead, covering his body, by 11:28 p.m.

Hoskins and McCall declined to provide the name of the officer involved in the shooting, saying only that he remains on paid leave and is dealing with anxiety related to the shooting.

The news conference came one day after protesters shut down the freeway near the site of the shooting, prompting police response.

“Protest should be peaceful, and we understand the constitution. There is no reason for the protesters to continue in the city of Berkeley unless they will not accept the fact that Mr. Martin drew his gun first,” Hoskins said. “We can only present the facts, and if they do not believe in that, that’s on them. The city of Berkeley will not tolerate what occurred last night.”

But that proclamation, partnered with the decision by Berkeley officials to not release the officer’s name, seems likely to further enrage protesters and some residents who remain skeptical about the circumstances of the shooting.

“Mayor says that blocking highways and streets ‘will not be acceptable from this day forward.’ That sounds like a challenge,” declared protest organizer DeRay Mckesson, who live-tweeted his reaction to the news conference. “This Mayor has just re-ignited the protests in Berkeley. I hope that we’re all ready for what he just started with that statement.”

Police also confirmed information about the arrest of Joshua Williams, a well-known 19-year-old Ferguson protester who they say has confessed to starting a fire at the QuickTrip gas station across the street from where Martin was killed on the night of the shooting.

Williams, who has been a near-constant presence at the Ferguson protests, has been charged with arson and burglary after store surveillance cameras and media footage captured images that appear to show Williams entering the gas station and attempt to start fires both inside and outside.

While Williams has never been a key organizer or leader of any of the protest groups that have emerged in the months since the Brown shooting, his energy  – often among those yelling loudest at elected officials and police during demonstrations – has made him one of the most photographed and interviewed of the protest regulars.

Critics of the budding protest movement have seized the charge – which appears to be the first charge of arson related to any of more than two dozen buildings that have been at least partially damaged on nights when protests have turned violent – to fuel their claim that the Ferguson demonstrators were never, in fact, peaceful protesters. Many of the most vocal and prominent protesters, however, have stood by Williams – beginning online fundraising efforts for his bail. Several expressed anger that Berkeley officials brought up Williams’s charges while providing relatively few new details about Martin’s fatal encounter with officers.

“It’s amazing how clear they can be about Josh and yet the events leading to Antonio Martin’s death are fuzzy,” tweeted Charles Wade, who has helped organize many of the Ferguson protests. “A press conference about Antonio Martin should be about Antonio Martin… Josh had nothing to do with Antonio Martin’s death.”