FILE – In this July 8, 2016, file photo, Dallas police chief David Brown, front, and Dallas mayor Mike Rawlings, rear, talk with the media during a news conference in Dallas. Nearly two months after the shootings, Dallas police have moved to silence critics and squelch lingering questions about the attack. Officers in riot gear […]

DALLAS (AP) – The day after five Dallas officers were killed by a sniper, the city’s police chief described the men as “guardians” of democracy, praising them for protecting the freedom to protest at a large demonstration against police brutality.

President Barack Obama later eulogized the slain officers, saying they died while defending essential constitutional rights.

But nearly two months after the shootings, Dallas police have moved to silence critics and squelch lingering questions about the attack. Officers in riot gear have been told to ticket protesters who block or disrupt traffic, and Police Chief David Brown has refused to meet with demonstrators unless they agree to end their marches through downtown, which he says pose a threat to officers.

Authorities have also refused to release even the most basic information about the slayings, including any details about the weapons used, the autopsy findings and ballistics tests that could establish whether any officers were hit by friendly fire. Police have indicated that such information could be withheld almost indefinitely.

In addition, the police department’s most vocal, visible critic – a 27-year-old self-styled preacher with a criminal history – has been arrested multiple times in the last month on warrants that include unpaid traffic tickets and attempts to revoke his probation from a 2009 felony. On Friday, Dominique Alexander was ordered to prison.

“Why all of a sudden are we the target?” asked Damon Crenshaw, vice president of the Next Generation Action Network, which organized the July 7 protest. “We’re not protesting because we’re mad at them. We’re protesting because the problems still exist and they won’t talk to us.”

Crenshaw said Alexander was targeted because of his protest activities and that the shooter, Micah Johnson, was not affiliated with their group.

Dallas has a history of cracking down on protesters.

During the Occupy Dallas demonstrations in 2011, the city tried to require protesters to have a $1 million insurance policy, strengthened rules against camping in the city and eventually evicted campers from City Hall in a midnight police raid.

In 2013, the city cited a decades-old rule prohibiting holding signs within 75 feet of major roadways to stop a group that planned to protest the opening of the George W. Bush Presidential Center. The city settled a lawsuit from that group before changing the law to prohibit protests on overpasses and other areas near highways. Another group sued over that law leading to another settlement, and the city repealed the rules all together.

Alexander, the founder of the protest network, believes he was targeted because he refused to stop the demonstrations.

“They try to hush and silence people,” he said. “It would be a failure to the lives lost if we don’t continue. The issues still exist, and they can act like they want to heal, but then they ignore the issues.”

The police chief has support from City Hall. Mayor Mike Rawlings said in a statement that he trusts Brown’s “judgment in how he communicates with protest organizers.”

Alexander, whose record includes convictions for forging a check, evading police and theft, was on probation for a 2009 conviction for causing injury to a child. He said the 2-year-old he was watching had fallen off the couch, but hospital staff said the child’s injuries were more consistent with abuse.

Alexander denied injuring the child and said he pleaded guilty because he could not afford a good attorney.

His uncle was killed by police in 2010 after firing on officers. But it was the 2014 death of a woman he knew in high school that prompted his involvement in police protests, Alexander said. The woman was missing for a week before being found dead in an abandoned building. Her family complained that police ignored their initial pleas for help.

Alexander spent the past two weeks under house arrest, wearing an ankle monitor and awaiting a judge’s determination of whether his probation would be revoked.

“No new crime has been committed to warrant this kind of action,” said Kim Cole, one of Alexander’s attorneys. “And the timing does appear suspicious.”

Just days after a July 29 silent protest – the first following the sniper attack – authorities asked that Alexander’s probation be revoked for a variety of violations, including twice leaving the state without notifying his probation officer, once to attend the Democratic National Convention in Philadelphia. Court records show the judge admonished Alexander and added 30 hours of community service to his sentence.

Then on Aug. 10, following a confrontational appearance at a city council meeting, Alexander was cited for trespassing and escorted out of City Hall, where officers were waiting to arrest him on nine outstanding traffic ticket warrants. He spent the night in jail and, within an hour of his release, another arrest warrant was issued in a new attempt to revoke probation. That request rehashed clprevious allegations from the past year, including missed meetings with his probation officer, for which Alexander had already served 10 days in jail in December.

At Friday’s hearing, the judge considered all of Alexander’s probation violations and sent him to prison for two years. With credit for time served, that comes to about six months, his attorneys said.

Prosecutor Douglas Millican denied that politics were behind the efforts to revoke Alexander’s probation. But Cole said Alexander got extra scrutiny because of his protest activities, noting that police and sheriff’s officers had provided the judge with social media posts and other photos and video of Alexander to show he had left the state.

In addition to the protest crackdowns, city and police officials have also succeeded in suppressing questions about the shooting, including details about the law enforcement response and the motive of the gunman, who was killed when police deployed a bomb-carrying robot. It was the first time law enforcement in the U.S. had used a robot to deliver and detonate an explosive to kill a suspect.

Authorities have refused public records requests for police reports, 911 calls, audio and video recordings, autopsy documents, crime scene photos and evidence gathered at Johnson’s house, which police initially said held an arsenal of weapons and bomb-making material and a journal of combat tactics possibly indicating plans for a larger attack. Other officials have told The Associated Press that Johnson did not have a large stockpile of bomb-making materials.

The Associated Press was informed by Dallas police late Friday that a portion of the records it requested would be made available, but the content was unclear.

Brown told the City Council earlier this month that much of the information about the attack could be withheld for an indefinite period during an investigation into whether the use of force was justified. He declined to estimate how long that investigation might take, but said his office’s findings would be reviewed by the district attorney and a grand jury.

The police chief did acquiesce to one of the protest network’s top demands, agreeing to eliminate a 2013 policy allowing officers 72 hours to give a statement after being involved in a shooting. The move, announced in a nighttime post to the department’s blog, said officers “will be provided the same legal rights as any other citizen who is the subject of a criminal investigation.”