(CNN) — Four Missouri police officers have been indicted by a federal grand jury in connection with the assault of a fellow officer who was working undercover.

Officers Dustin Boone, Randy Hays and Christopher Myers with St. Louis Metropolitan Police Department (SLMPD) are accused of beating the undercover officer with a riot baton and tampering with witnesses to cover up the incident, according to the Department of Justice. Myers was also charged with destroying evidence. Officer Bailey Colletta was indicted on a charge of providing false statements to a federal grand jury in connection with the incident.

The indictment also details text messages between Myers and Boone in which they talk about how much fun it will be to beat “the hell out of these s**theads once the sun goes down and no one can tell us” apart.

CNN attempted to reach the city of St. Louis, the SLMPD and associations representing the officers, but has not received a response.

In September 2017, all four officers were assigned to a Civil Disobedience Team, which conducts crowd control, in anticipation of a protest against the acquittal of Officer Jason Stockley, the US Department of Justice said in a news release.

Stockley was a St. Louis police officer in 2011 when he fatally shot a black driver, Anthony Lamar Smith, after a police chase. Stockley, who is white, claimed he was acting in self-defense because he believed Smith was reaching for a gun. Prosecutors argued that Stockley planted the gun to justify the shooting.

When Stockley was acquitted in 2017, protests broke out in St. Louis. A 22-year veteran of the St. Louis Police Department — referred to in the indictment as L.H. — was in the crowd working undercover as a protester to document crimes among the demonstrators so law enforcement could make arrests, according to the indictment.

The indictment alleges that Boone, Hays and Myers threw L.H. to the ground without probable cause and began to kick him and strike him with a riot baton.

According to Thursday’s indictment, L.H. “was an experienced undercover officer who specifically wore a shirt that revealed his waistband so that he would not be mistaken for being armed.”

Once Myers, Boone and Hays learned that L.H. was a police officer, the indictment says, they made false statements justifying the assault, contacted L.H. to dissuade him from taking legal action and contacted witnesses to try to influence their testimony.

Myers also destroyed L.H.’s cellphone “with the intent to impede, obstruct, and influence the investigation,” according to the indictment.

Text messages

Most of the text messages in the indictment between Myers, Boone and Hays include expletives.

“We really need these f**kers to start acting u(p) so we can have some fun,” Boone texted, after they determined they were going to be on the same team.

“A lot of cops getting hurt, but it’s still a blast beating people that deserve it,” said another text from Boone.

He also remarked that he would be working with a black officer and referred to him as “a thug that’s on our side.”

‘Veered’ off

Officer Colletta — who was in a romantic relationship at the time with Hays, the indictment said — was on the team that night and offered inconsistent explanations as to why they arrested L.H., according to the indictment.

Initially, Colletta said she had never come into contact with L.H. that night. Then, she asserted that she witnessed the arrest and saw L.H. taken to the ground “very gently.”

Colletta also said the group had “veered off” to arrest L.H., according to the indictment. The next day, she said she learned from her sergeant that they had stopped L.H. because he fit the description of a radio dispatch.

In a later statement, she claimed she didn’t recall anyone saying that.

The DOJ says the arrest and assault of L.H. amounts to a deprivation of his civil rights.

One of the charges carries a maximum sentence of 10 years in prison. The other three carry a maximum of 20 years. All four counts have a maximum of $250,000 in fines.

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