Arrest: Jefferey Williams (pictured in his mug shot) has been charged in connection with the shooting of two police officers in Ferguson last week . A 20-year-old African-American man has been arrested and charged in connection with last week's shooting of two police . officers during a protest in Ferguson, Missouri. Jeffrey Williams, who was involved in the demonstrations, is accused of two counts of assault on a police officer, firing a weapon out of a vehicle and three counts of armed criminal action in relation to the incident on Thursday. If convicted of the crimes, he faces life in prison. The shooting sent a fresh jolt of tension through a city that became a symbol of racial conflict after black teenager Michael Brown was killed by white officer Darren Wilson last summer . A grand jury later returned no criminal charges. On Sunday, Robert McCulloch, St Louis County prosecutor, said  Williams  admitted to officials that he had fired a gun. However, the suspect claimed he was trying to hit someone else with whom he was arguing, Mr McCulloch said. 'We're not sure we completely buy that part of it,' the prosecutor said at a press conference, adding there might have been other people in a vehicle Williams is accused of shooting from. Mr McCulloch also confirmed that shell casings that were found at the scene have been linked to a handgun that was taken off of Williams. At the time of the shooting there was a warrant out for the suspect's arrest after failing to show up to sessions with his probation officer. He had been convicted for receiving stolen goods. It comes as anti-police protesters have resumed demonstrations outside Ferguson police station. Many were seen arguing with pro-authority demonstrators and officials on Sunday afternoon. One masked protester even ripped up an American flag as he condemned the police force. In the shooting early on Thursday, a 41-year-old county police officer suffered a shoulder wound . Scroll down for video . Statement: St. Louis Robert McCulloch (pictured announcing Williams's arrest) said the suspect admitted to officials that he had fired his gun. However, he said he was trying to hit someone else, Mr McCulloch said . Blood-spattered: 'We're not sure we completely buy that part of it,' the prosecutor said at a press conference. Above, police shine a light on a helmet as they investigate the scene where two police officers were shot . Wounded: In the shooting early on Thursday, a 41-year-old county police officer suffered a shoulder wound. Another officer, 32, suffered a facial wound. Above, one of the officers  is seen being taken away by EMT . Meanwhile, his 32-year-old colleague from a nearby police department sustained a facial wound after a bullet tore through his skin and became lodged near his ear. Both were treated and released by a local hospital. The pair have been told that a suspect is in custody. Mr McCulloch said Williams used a 40mm handgun on the night of the shootings. Williams is being held on $300,000 bond. The north St. Louis County resident was on probation in St. Louis County for receiving stolen property, Mr McCulloch said. 'I think there was a warrant out for him on that because he had neglected to report for the last seven months to his probation officer,' he said during Sunday's press conference. It comes as anti-police protesters (pictured) have resumed demonstrations outside Ferguson police station . Many were pictured arguing with pro-authority demonstrators and police officers (pictured) on Sunday night . Opposing sides: Pro-police demonstrators protest outside Ferguson police station on Sunday afternoon . On Thursday, St. Louis County Police Chief Jon Belmar said the officers could have easily been killed in the shooting, which came amid protests in Ferguson over alleged police violence. Chf Belmar also called the attack 'an ambush,' citing the two New York City officers who were shot and killed in their police cruiser in December. Attorney General Eric Holder said in a statement Sunday that the arrest 'sends a clear message that acts of violence against our law enforcement personnel will never be tolerated'. He also praised 'significant cooperation between federal authorities and the St. Louis County Police Department.' St. Louis County Police Chief Jon Belmar said the officers could have easily been killed in the shooting, which came amid protests in Ferguson over alleged police violence. Above, a Michael Brown supporter . Dispute: A pro-police protester, left, and counter protester yell at each other outside Ferguson police station . Tense: A Ferguson officer separates pro-police and anti-police protesters outside the police headquarters . Ongoing protests: Demonstrators confront police during the protest over alleged police brutality. The police department has been a national focal point since the fatal August 9 shooting of unarmed teen Michael Brown . The police department has been a national focal point since the fatal August 9 shooting of Michael Brown, who was black and unarmed, by now-former police officer Darren Wilson. Officer Wilson was cleared by the Justice Department's report and a grand jury led by McCulloch declined to indict him in November. The federal report found widespread racial bias in the city's policing and in a municipal court system driven by profit extracted from mostly black and low-income residents. Six Ferguson officials, including Jackson, have resigned or been fired since the federal report was released March 4. An investigation into Thursday's shooting is ongoing. 'I love Ferguson': Pro-police demonstrators protest outside Ferguson police station on Sunday afternoon . One of the protesters held a sign reading 'Go home media circus', while others showed support for the Mayor . Torn up: An American flag lies in the dirt after being ripped apart by anti-police demonstrators on Sunday . Shooting: Police take cover after two officers were shot while standing guard in front of the Ferguson Police Station last Thursday .
Jeffrey Williams is currently in custody at St Louis County police station . He was at the demonstration last Thursday when two officers were shot . Prosecutors say he admitted to officials that he fired a gun on the night . However, Williams claimed he was trying to hit someone else, they say . Two officers gunned down and injured in Ferugson, Missouri, last week . Both were treated for wounds and subsequently released from hospital . Williams was on probation for receiving stolen goods at time of incident . Comes as anti-police and pro-police protesters continue to demonstrate .