Updated

The indictment of four St. Louis police officers provides a troubling glimpse into the mindset of officers who were eager to rough up protesters during a tumultuous period in 2017, civil rights leaders said Friday.

The federal indictment announced Thursday accuses officers Dustin Boone, Randy Hays and Christopher Myers of attacking an undercover colleague during a 2017 protest, not knowing he was an officer, and trying to obstruct the investigation. Officer Bailey Colletta was accused of lying to a federal grand jury.

St. Louis was besieged by protests after the Sept. 15, 2017, acquittal of Jason Stockley, a white former police officer charged in the 2011 death of a black man, Anthony Lamar Smith. Stockley claimed Smith, 24, had a gun and he fired in self-defense; prosecutors said Stockley planted the weapon in Smith's car at the end of a pursuit.

Two nights after the acquittal, demonstrators broke windows and turned over flower pots downtown. Police eventually used a technique known as "kettling" to make 123 arrests. In kettling, police form barriers and gradually move in on suspects.

Protest and civil rights leaders said many of those caught up in the kettle were peaceful protesters, journalists and onlookers. Police were accused of brutalizing and taunting many of those arrested.

The indictment said electronic messages shared between the accused officers expressed disdain for protesters and excitement "about using unjustified force against them and going undetected while doing so."

Several of the messages cited in the indictment were attributed to Boone. On the day of Stockley's acquittal, Boone allegedly wrote, "The more the merrier!!! It's gonna get IGNORANT tonight!! But it's gonna be a lot of fun beating the hell out of these (expletives) once the sun goes down and nobody can tell us apart!!!!"

Critics have long raised concerns that many officers removed name tags during the protests, making identification difficult.

"The text messages confirm our suspicions that these officers were using the anonymity of their SWAT uniforms and face masks after removing their name tags so that they could beat citizens with impunity," said Javad Khazaeli, an attorney whose law firm has filed suit against police on behalf of 23 people arrested in protests.

Later on Sept. 15, 2017, Boone allegedly wrote, "We really need these (expletives) to start acting up so we can have some fun."

The Rev. Darryl Gray, a black activist who organized many of the Stockley protests, believes other officers not named in the indictment had similar attitudes toward demonstrators.

"Those three made it very clear that it wasn't just a discussion, it was an attitude," Gray said. "They were going to act out their aggression, they were going to act out their violence, they were going to act out their disregard for the law and the civil liberties and rights of people."

The indicted officers were part of the police department's Civil Disobedience Team, which included more than 200 officers responding to the protests.

A 22-year police veteran identified only as L.H. also was part of the team, but working undercover. The indictment accused Boone, Hays and Myers of throwing L.H. to the ground, hitting him with a baton, kicking him. A police spokeswoman said the undercover officer is still with the department but wouldn't say if he has recovered from his injuries.

All four officers made their first court appearances Friday. The St. Louis Post-Dispatch reported they were shackled at the wrists and ankles. They were released on their own recognizance but U.S. Magistrate Judge Noelle Collins told them to remove any guns from their homes within 24 hours. Attorneys for the officers declined comment.

Meanwhile, Democratic state Sen. Jamilah Nasheed of St. Louis called for the Missouri Department of Public Safety to suspend the officers' licenses immediately.

"I am appalled by the unethical, out of control, and vicious behavior of these officers. The text messages released last night show these individuals were more interested in terrorizing our community than protecting it," Nasheed, who is black, said in a statement.

Police Chief John Hayden said in a statement he was "deeply disappointed" by the allegations, but they are "in no way reflective of the hard work and dedication exhibited by the men and women of our Department who serve the community on a daily basis with integrity and honor."

Tony Rothert, legal director of the ACLU of Missouri, urged St. Louis leaders to "address this rampant lawlessness by its police."

"While these officers have been indicted for illegally abusing an undercover officer they mistook for a protester, there has still been no real accountability for the individuals officers who engaged in the same behavior toward protesters," Rothert said in a statement.