State Sen. Will Espero wants the Attorney General’s Office to investigate allegations that a sheriff’s deputy squirted pepper spray in the face of a handcuffed prisoner seated in the back of a patrol vehicle at the Honolulu airport about five years ago and that sheriff’s officials failed to properly investigate the incident.

It is unclear why those allegations are being investigated now, but documents provided by Espero show a deputy who witnessed the aftermath of the spraying was instructed last month to prepare a report on the incident for Department of Public Safety Director Nolan Espinda.

Espero, Senate majority floor leader, wrote to Espinda on Monday to ask what is being done about the allegations. “From my perspective, the incident could be a criminal assault and a violation of one’s civil rights if it indeed did occur,” wrote Espero (D-Ewa Beach-Iroquois Point).

“It really looks like there possibly could have been a cover-up here or a lack of follow-up,” Espero said in an interview.

Espero said he suggested that the attorney general review the case because “just the allegation that someone may have covered it up, already you have an agency investigating itself, and from a public perspective, that’s just really not the visual that people will have faith in or trust because of the seriousness of the situation.”

According to documents provided by Espero, Deputy Sheriff Richard Stevenson complained in writing on March 22, 2016, to then-Sheriff Renee Sonobe Hong about the handling of the incident and complained again to Espinda on Sept. 17, 2017. Hong is now Public Safety’s deputy director for law enforcement.

Stevenson wrote in September that he is “greatly concerned and appalled that the Department of Public Safety, Sheriff Division have done NOTHING to the best of my knowledge to address, investigate or otherwise hold accountable certain individuals for reported CRIMINAL ACTIONS, CIVIL RIGHTS VIOLATIONS as well as Standard of Conduct violations.”

Stevenson referred to memos he wrote in 2016 raising concerns about the pepper spay incident, and wrote that “the culture of POLICE CORRUPTION AND COVER UPS as well as SELECTIVE ENFORCEMENT is well and alive in the Sheriff Division/Sheriff Airport Section.”

Stevenson also complained in 2016 that an administrative investigation of the incident was assigned to one of the sergeants who stood by while it happened and did not intervene to help the prisoner, according to documents released by Espero.

Stevenson declined to discuss his concerns Monday, saying he is not authorized to speak with the media.

The documentation released publicly by Espero includes a Sept. 28 report by Deputy Sheriff Brian Brunn of the airport section describing a series of events following a traffic stop of an African-American motorist on Waiwai Loop near the airport.

According to Brunn’s report, the deputies arrested the unidentified motorist in connection with an outstanding warrant, handcuffed him and placed him in the back seat of a sheriff’s patrol vehicle to take him to the airport receiving station.

When Brunn arrived at the receiving station later, he found two other deputies watching a video of the arrested man being pepper-sprayed in the back of the patrol car at the receiving station, according to Brunn’s report.

The video, Brunn said, showed a deputy yelling at the prisoner and spraying him before slamming the car door with the prisoner inside. It also showed a sergeant who had been standing on the opposite side of the patrol car suddenly run away from the car, according to Brunn’s statement.

Brunn told another deputy to make a copy of the video and give it to another sergeant, according to the statement. He then entered the cell where the motorist was being held and used wet paper towels to “detox” his eyes, face and nose, according to the report.

The motorist had a swollen eye and told the deputy he was injured when his head was shoved into a faucet as he was bent over a sink, according to the report. The motorist said he wanted to file a complaint about his mistreatment but was told by a sergeant that he could not, according to Brunn.

Brunn told the sergeant that “this is wrong” and told the prisoner to file a complaint with the department’s Internal Affairs office. He also reported the incident to two other sergeants, according to his report. Brunn said in his report he does not recall the arrested man’s name, and no date for the incident was given in his report.

A spokeswoman for the Department of Public Safety said the incident allegedly happened before February 2013 and “was brought to the current Public Safety administration’s attention in March 2016.”

“Any allegations of a cover-up are taken seriously by this administration, however, until it is concluded, we will not be sharing any information from the currently open investigation,” the spokeswoman said in a written statement.

Joshua Wisch, special assistant to Attorney General Doug Chin, said in an email that his office “just recently received the request from Senator Espero and are currently reviewing it. There’s nothing further we can say at the moment.”