A Denver sheriff’s deputy who provoked a fight with an inmate by using taekwondo kicks and punches has been suspended for 90 days.

Deputy Roberto Roena received his suspension July 29 for the fight that occurred in April 2013, according to his disciplinary letter obtained by The Denver Post. Roena was punished for using excessive force and making inaccurate and misleading statements about the incident, the letter said.

The 15 months it took to discipline Roena supports a common complaint that it takes too long for deputies to be punished after they break a department policy. A recent Post analysis of disciplinary records from January 2012 to mid-July 2014 found that it takes longer than 10 months for the typical case to be adjudicated.

Sheriff’s department internal investigators determined that Roena had provoked a fight with inmate John Cardenas, who had a reputation as a violent inmate.

According to Roena’s disciplinary letter, Cardenas was angry because he and other inmates were told they only had a 30-minute break outside their cells rather than an hour. Cardenas had been making threats, but the deputies guarding the cell appeared to ignore him and had left a sliding security door open.

Roena, a 15-year department veteran, was on court duty the day of the fight but had gone to a cell block at the Downtown Detention Center to visit other deputies. He spoke to the other deputies about his fitness and exercise routine, which included martial arts.

Roena was a taekwondo instructor and, in 2012, had been invited to Cuba to teach a class on the martial art, the disciplinary letter said.

Roena set down a drink and performed a taekwondo sidekick into the air, according to video footage. Cardenas taunted Roena, telling him “that isn’t a kick,” the disciplinary letter said.

Roena then turned toward the inmate, raised his hands into a fighting position and lifted his foot in a partially extended kick, according to the letter and video footage.

The inmate extended his hands through an open door in what appeared to be an attempt to counter the deputy’s moves.

The fight escalated as Roena threw a fully extended sidekick toward the inmate’s head.

The two briefly separated and began grappling. The fight spilled through the open door and into the hallway as Roena put the inmate in a headlock, according to the letter and video.

The two hit the ground, and other deputies rushed to help Roena.

After the fight, Roena wrote in a mandatory use-of-force report that Cardenas was the aggressor.

Roena said he responded with defensive tactics, including the side kick, to protect himself.

However, the video told a different story, the letter said.

“At the time of the initial interaction, inmate Cardenas posed no objectively reasonable threat to Deputy Roena’s safety,” the letter said. “It was only after Deputy Roena’s poor decision to engage inmate Cardenas that inmate Cardenas demonstrated potentially physically aggressive behavior.”

If Roena had felt threatened, he could have closed the sliding door or asked the four other deputies in the area for help, the letter said.

Efforts to reach Roena’s attorney were unsuccessful.

In a meeting with sheriff’s department leaders, Roena said it was a mistake to demonstrate martial arts techniques in the detention center, the letter said.

“You said this incident was an unfortunate circumstance that resulted from mistakes that you made at work,” the letter said. “You apologized for your mistakes, for the incident happening, and explained that you did not intend for the incident to happen and did not act out of malice.”

A string of excessive-force cases led Mayor Michael Hancock this summer to launch a massive effort to reform the sheriff’s department. In July, the city was forced to pay out the largest lawsuit settlement in its history after it agreed to award $3.25 million to former inmate Jamal Hunter for abuses he suffered in the jail.

On Tuesday, the department fired a deputy who was filmed as he grabbed Hunter by the neck and shoved him onto a cell bunk. A second deputy who punched and kicked an inmate during the booking process at the downtown jail also was fired.

Roena’s case is the latest to surface. He had no prior disciplinary issues at the department but received a strong warning that further misconduct would be dealt with “harshly and severely.”

“The Department has a great concern regarding your ability to act responsibly and to conduct yourself appropriately as a Denver Sheriff Department Deputy,” the letter said.