FERGUSON, Mo. — Lawyers for Michael Brown’s family vowed Tuesday to push for federal charges against the police officer who killed the unarmed 18-year-old, while the officer insisted in his first public statements that he could not have done anything differently in the confrontation.
As darkness fell, hundreds more National Guardsmen were ordered into Ferguson in hopes that their presence would help local law enforcement keep order in the St. Louis suburb.
During an interview with ABC News, Wilson said he has a clean conscience because ‘‘I know I did my job right.’’
Wilson, who has been on leave since the Aug. 9 shooting, had been with the Ferguson police force for less than three years. He told ABC that Brown’s shooting marked the first time he had fired his gun.
The Brown family lawyers said the grand jury process was rigged from the start to clear the white officer, Darren Wilson, in the Aug. 9 shooting death of Brown, who was black. They criticized everything from the evidence the St. Louis County prosecutor presented, to the way it was presented, as well as the timing of the announcement of the grand jury’s final decision.
‘‘We said from the very beginning that the decision of this grand jury was going to be the direct reflection of the presentation of the evidence by the prosecutor’s office,’’ lawyer Anthony Gray said. He suggested the county’s top prosecutor, Bob McCulloch, presented some testimony to discredit the process, including from witnesses who did not see the shooting.
Twelve commercial buildings in Ferguson burned down during protests that erupted after the grand jury’s decision was announced, and firefighters responded to blazes at eight others, fire officials said. Other businesses were looted, and 12 vehicles were torched.
In the aftermath of Monday night, Governor Jay Nixon more than tripled the number of National Guard troops in Ferguson, ordering the initial force of 700 to be increased to 2,200.
‘‘Lives and property must be protected,’’ Nixon said. ‘‘This community deserves to have peace.’’
McCulloch’s decision to announce the grand jury decision in the evening drew complaints from many who wondered whether that helped fan the flames of unrest and violence leading to destruction in the St. Louis suburb.
McCulloch’s news conference began just before 8:30 p.m. Monday, during which he disclosed that Wilson would not face indictment.
By the time of the announcement, many protesters had already gathered in Ferguson. Disorder broke out moments after McCulloch announced that Wilson would not face charges.
Brown’s mother, Lesley McSpadden, and stepfather, Louis Head, stood with protesters outside the barricaded Ferguson police station as McCulloch made the decision public. As McSpadden cried, Head turned and yelled, with an expletive injected, “Burn this down!”
The crowd began to roar, and some demonstrators rushed toward a fence near which police officers had assembled.
Almost on cue, right after McCulloch said that Wilson would not be charged, cars began flooding what was an empty West Florissant Avenue.
The decision to announce at night was McCulloch’s alone, Governor Jay Nixon said Monday. McCulloch spokesman Ed Magee concurred, and he defended the decision.
‘‘We coordinated with law enforcement, gave schools time to get the children home and in a safe location, gave businesses time to make a decision regarding the safety of their employees,’’ Magee said.
Former two-term Ferguson mayor Brian Fletcher, who now leads the ‘‘I Love Ferguson’’ campaign to help restore the community, called the timing ‘‘horrible.’’
‘‘I don’t understand why it wasn’t done in the early morning hours of 4 a.m. or 5 a.m.,’’ Fletcher said. ‘‘You could still call off school and there would have been a full day of daylight for law enforcement to get into position to prevent the unrest and ultimate destruction of our city.’’
Protests continued Tuesday. In Clayton, where the grand jury met, clergy members and others blocked morning traffic for several hours. In downtown St. Louis, where demonstrators swarmed the steps of a federal courthouse and stopped traffic, at least four people were arrested.
Lawyers for Brown’s family said they hope an ongoing federal civil rights investigation leads to charges. But federal investigations of police misconduct face a steep legal standard, requiring proof that an officer willfully violated a victim’s civil rights.
Testimony from Wilson that he felt threatened, and physical evidence such as the discovery of Brown’s blood in Wilson’s patrol car, almost certainly complicate any efforts to seek federal charges.
The Justice Department has also launched a broad probe into the Ferguson Police Department, looking for patterns of discrimination.
Material from The New York Times was used in this report.