ROSENBERG, Texas -

A police lieutenant is out of a job and three of his colleagues have been disciplined after an officer was injured in what the chief calls a hazing initiation incident for a new SWAT team member. The lieutenant involved denies it was a hazing incident.

Surveillance video obtained by Local 2 Investigates shows several officers watching another officer fire a 40 mm "less-lethal" bean bag round at Officer Erik Marmol.

Marmol was wearing protective gear on his head and torso, but the round hit him in an unprotected part of his leg. An image of Marmol's leg, taken days after the incident and released to Local 2, shows a large bruise with a section of skin that appears to be torn.

Officers can be heard on the video laughing after Marmol screams. One person can be heard saying, "I'll bring your pin tomorrow."

"This can only be characterized as a hazing incident, an initiation incident. I think that type of behavior cannot be tolerated," Chief Dallis Warren said.

The incident happened outside the Rosenberg police station in May, but was made public in a Local 2 Investigation Wednesday.

Lt. Aaron Slater was initially fired by Warren, but was later allowed to resign. Sgt. Sean DeRoch was demoted to patrolman and removed from the SWAT team. Sgt. William Henry was given a written reprimand and Officer Stephen Clarke was given two weeks of unpaid suspension and removed from the SWAT team, according to Rosenberg contract-City Attorney Scott Tschirhart. DeRoach is appealing his discipline, but a hearing before the chief has not been scheduled.

Warren said, after the incident, not all officers were completely forthcoming with information.

"I don't think I was told the truth initially, but what's important is that the truth eventually came out," he said. "There were discrepancies in (the officers' statements) and I think that's the reason for the range of disciplinary action you saw."

Warren said Slater did not alert him to Marmol's injuries for two days, despite Marmol not coming to work during that time.

Slater, who is now out of a job, said he was not made aware of the severity of Marmol's injuries until the day he notified the chief.

Slater also said the incident happened during a training demonstration and he has never lied about the incident.

"This wasn't a hazing incident. It was never intended to be a hazing incident," Slater told investigative reporter Jace Larson.

Slater said a SWAT team member, who he supervised, wanted to order more training rounds and Slater asked whether he could demonstrate how the current rounds work.

"An officer walked in. I asked the question. I asked if he'd be willing to take a round and he said, 'Well as long as all the safety precautions are there.' We discussed what safety precautions there would be," Slater said. "I made a comment in jest: 'It's part of the initiation to the SWAT team.' We immediately joked. We laughed about it. It was obviously not the case."

Slater said he is not making excuses and admits mistakes were made the day Marmol was injured.

"Doing it to begin with may have been a mistake," Slater said. "However, this type of spontaneous training happens all the time."

He claims the chief has had it in for him since both men applied to be the new chief. The City Council unanimously selected Warren for the job earlier this year.

"From the time he got appointed in March, it was constant retaliation for me ultimately applying for the position," Slater said.

Slater filed a 20-page grievance in April, but said the city council determined there was not enough evidence to move forward with the allegations in the grievance.

Slater said he feels he should have only been suspended.

"I've never been disciplined in my entire life," he said. "I'm a very rewarded, well-respected officer in the community."

Have a story idea for investigative reporter Jace Larson? Email him or send him a message on Facebook.