FLORISSANT, Mo. (AP) — The Missouri State Highway Patrol will take over supervising security in the St. Louis suburb that’s been the scene of violent protests since a police officer fatally shot an unarmed black teenager, the governor announced Thursday.

Gov. Jay Nixon made the announcement that security will be overseen by Capt. Ron Johnson of the Highway Patrol after the local police response drew heavy criticism. Nixon said the change is intended to make sure “that we allow peaceful and appropriate protests, that we use force only when necessary, that we step back a little bit and let some of the energy be felt in this region appropriately.”

Johnson, who is black, said he grew up in the community and “it means a lot to me personally that we break this cycle of violence.”

“Ferguson will not be defined as a community that was torn apart by violence but will be known as a community that pulled together to overcome it,” Nixon said at a news conference.

Crowds have gathered to protest since Saturday’s shooting of 18-year-old Michael Brown. On Sunday night, some residents were seen looting stores, damaging buildings and vandalizing property. Since then, officers from multiple departments in riot gear and in military equipment have clashed nightly with protesters, who chant, “Hands up, don’t shoot,” a reference to witness accounts that Brown had his hands raised when he was shot.

Police have used tear gas and smoke bombs to disperse large crowds, including on Wednesday night when some people threw Molotov cocktails and rocks at officers.

Nixon, who has faced increasing criticism over suggestions he has not done enough to calm tensions, said local police will still be involved in providing security, but under state supervision.

Earlier Thursday, President Barack Obama appealed for “peace and calm” on the streets.

“I know emotions are raw right now in Ferguson, and there are certainly passionate differences about what has happened,” Obama said. “But let’s remember that we’re all part of one American family. We are united in common values, and that includes the belief in equality under the law, respect for public order and the right to peaceful public protests.”

Obama, speaking from the Massachusetts island where he’s on a two-week vacation, said there was no excuse for excessive force by police in the aftermath of the shooting. He said he had asked the Justice Department and FBI to investigate the incident.

St. Louis County police spokesman Brian Schellman said officers on Wednesday night tossed tear gas to disperse a large crowd of protesters after some threw Molotov cocktails and rocks at officers. More than 10 people were arrested in Ferguson.

“In talking to these guys, it is scary,” Schellman said of officers on the front lines of the protest. “They hear gunshots going off, and they don’t know where they’re coming from.”

Residents in Ferguson have complained about the police response that began soon after Brown’s shooting with the use of dogs for crowd control — a tactic that for some evoked civil-rights protests from a half-century ago. The county police force took over, leading both the investigation of Brown’s shooting and the subsequent attempts to keep the peace at the smaller city’s request.

County Police Chief Jon Belmar said his officers have responded with “an incredible amount of restraint” as they’ve had rocks and bottles thrown at them, been shot at and had two dozen patrol vehicles destroyed.

The city and county are also under criticism for refusing to release the name of the officer who shot Brown, citing threats against that officer and others. The hacker group Anonymous on Thursday released a name purported to be that of the officer, but the Ferguson police chief said later that the name was incorrect.

Twitter quickly suspended the Anonymous account that posted the officer’s purported identity and personal information. The site’s code of conduct strictly forbids the publication of private and confidential information without permission.

Police have said Brown was shot after an officer encountered him and another man on the street. They say one of the men pushed the officer into his squad car, then physically assaulted him in the vehicle and struggled with the officer over the officer’s weapon. At least one shot was fired inside the car. The struggle then spilled onto the street, where Brown was shot multiple times.

The officer involved was injured, with one side of his face swollen, Jackson said.

Dorian Johnson, who says he was with Brown when the shooting happened, has told a much different story. He has told reporters that the officer ordered them out of the street, then grabbed his friend’s neck and tried to pull him into the car before brandishing his weapon and firing. He says Brown started to run and the officer pursued him, firing multiple times.

Johnson and another witness both say Brown was on the street with his hands raised when the officer fired at him repeatedly.