Hours before Chicago Police Officer Dina Markham was found dead in her bathtub in May, she sent a previously undisclosed text message.

Authorities won’t say what she said. But the Chicago Sun-Times has confirmed whom she texted: the police commander whose detectives had concluded that Markham’s police-officer husband killed himself in the same home in 2015 — a death that was under investigation by the FBI, which suspects Sgt. Donald Markham was murdered.

The commander, Kevin Duffin, showed up at Dina Markham’s Far Northwest Side home after her body was discovered on May 28. Duffin volunteered to a detective assigned to investigate her death that he’d gotten a text from her earlier that day, according to police records and sources — one of many text messages he said they had exchanged over the past six months.

Duffin also told the detective the FBI was investigating the death 21 months earlier of Donald Markham, as well as the way that detectives working under Duffin’s command had handled that case, according to the newly obtained information.

At the time of her husband’s death, Dina Markham was working in the department’s Bureau of Internal Affairs, which investigates police misconduct. She later was transferred to the Area North detective division, working for Duffin until at least a week before she died.

The text messages are mentioned in police reports the department had previously refused to make public. The department released them only after the Sun-Times sued for the records, but it blacked out Duffin’s name. Police officials later acknowledged Dina Markham and Duffin had been exchanging texts after Sun-Times reporters pressed them on the matter.

The police reports don’t say what was said in the texts or whether the messages involved professional or personal matters.

“The text messages were not part of CPD’s investigation as they had no contributing factor to the . . . death of Dina Markham,” police spokesman Anthony Guglielmi said. “The text messages between Commander Duffin and Markham were treated . . . as personal information between colleagues.”

Duffin, 59, has declined repeated interview requests. He’s been with the police department since 1982. Duffin no longer oversees the Area North detective division, which remains under scrutiny. In early September, he was reassigned to the Office of Emergency Management and Communications, which operates the city’s 911 system.

An FBI supervisor, Michael Brown, showed up at Dina Markham’s house on the day she died, police records show. But the FBI would not discuss the case.

Sgt. Donald Markham and Officer Dina Markham. | Facebook

On the day Donald Markham died — Sept. 2, 2015 — his wife made several frantic calls to 911, starting at 3:06 a.m., saying he was “bleeding” and unresponsive at their home in the 5900 block of North Newark in upscale Old Norwood Park, a neighborhood that’s home to many city workers.

Officers found Donald Markham, 51, dead on his bed with a bullet wound to the head.

Dina Markham told officers she and her husband, who worked in the narcotics division, had been out drinking and got into an argument because he wanted to go home, according to police records.

She also said she had been locked out of the house and that one of the couple’s five children let her in through a window so she could retrieve her car keys and sleep in their car, according to the records. They show she told investigators she found her husband on the bed in their dimly lit room while looking for the keys, that he was fully clothed and bleeding from his head.

Lt. Denis Walsh responded and took control of the crime scene, which included as many as 20 police officers. At 4:35 a.m., the now-retired Walsh sent a text message to Duffin, his supervisor, saying, “Call me so I can give you better directiond [sic].”

Less than an hour later, officers moved Donald Markham’s body from the home to the back of a police squadrol and drove it to the county morgue.

Though a Cook County ordinance requires someone from the medical examiner’s office to go to the scene of any violent death, no one did, county officials say, because the agency wasn’t notified until the body already was en route to the morgue. In an earlier interview, Walsh disputed that.

It’s unusual for the police to transport a body to the morgue. The department has a contract with a private company to do that.

Donald Markham’s bloody mattress was quickly removed from the house and dumped in the alley behind the Jefferson Park police station at 5151 N. Milwaukee.

The Chicago Police Department’s Jefferson Park station. | Google

A woman who identified herself as a cop called the ward superintendent for the city Department of Streets and Sanitation and asked for a special pickup, the Sun-Times has reported. A garbage truck showed up at 6:45 a.m. and hauled off the mattress.

Less than four hours after Dina Markham called 911, it was on its way to a landfill, though it would be days before police and the medical examiner’s office formally concluded that Donald Markham killed himself.

Hours after Donald Markham died, then-Deputy Chief of Detectives Eugene Roy emailed Duffin and Walsh, instructing them to fulfill the medical examiner’s request for recordings of Dina Markham’s 911 calls. Six days later, the office still had not received them. The medical examiner’s office eventually got them.

Months later, in June 2016, records show Duffin accessed the electronic file on Donald Markham’s death.

In July 2016, Dina Markham was transferred from internal affairs to Duffin’s Area North detective division.

Cmdr. Kevin Duffin. | James Foster / Sun-Times

Duffin accessed the Donald Markham case files again in November 2016 and in February 2017, when he printed the reports, records show.

Someone tipped off the FBI sometime last year or early this year that Donald Markham might have been murdered. Agents began investigating, came to suspect that Donald Markham didn’t kill himself and urged the police to open an internal affairs investigation.

But because Dina Markham worked in the bureau at the time of her husband’s death, the police department instead referred the case to the city’s inspector general, Joseph Ferguson, who opened an investigation earlier this year of the department’s handling of the Donald Markham case. That investigation is ongoing.

After learning of the FBI’s suspicions, Sun-Times reporters briefly spoke with Dina Markham at her home on May 22. She said she was unaware her husband’s death was being re-examined by the FBI and needed a day to decide whether to discuss the case.

When she hadn’t responded two days later, the reporters returned, and she said she still needed more time.

She sent an email the next day saying “a friend of a friend” would be in touch. That didn’t happen.

Three days later, around 6 p.m. on May 28, Dina Markham, 47, was found dead in her bathtub by one of her five children and two of her friends, one who had received a text from Dina Markham early that morning that said, “Help. Please . . . no kidding.”

Since the FBI and the inspector general’s office were still investigating the way Duffin’s detectives handled Donald Markham’s death, the police department assigned Dina Markham’s death investigation to Area South, one of the department’s three detective units.

Duffin was among the officers who showed up at the Markham home, where he told an Area South detective about the text from Dina Markham earlier that day, as well as the FBI’s interest in Donald Markham’s death, the newly released records show.

In releasing its reports on Dina Markham’s death, lawyers for the city blacked out the name of the man who told the Area South detective about the FBI probe and the text messages he exchanged with Dina Markham. But sources told the Sun-Times it was Duffin.

“After the scene investigation was completed [the Area South detective] was approached by [name redacted, who] informed [the Area South detective] that the phone of [Dina] Markham will contain text messages between [Dina] Markham and [name redacted,]” a police report says.

The Area South detective “was further informed by [name redacted] a text message from [Dina] Markham to [name redacted] was received in the early morning hours on the day of [Dina] Markham’s death. [Name redacted] informed [the Area South detective] the communications have been going on for approximately six months. [Name redacted] also alluded to . . . a federal investigation into the death of Sgt. Donald Markham . . . was currently being conducted.”

At first, the police were investigating Dina Markham’s death as a suicide. But the medical examiner’s office ruled she accidentally drowned in her bathtub after drinking alcohol and taking an anti-anxiety drug, and the police closed the case Aug. 9.

PAST COVERAGE:

• Garbage man told: Dump bloody mattress ASAP in mysterious cop death, Oct. 8, 2017

• Chicago cop couple’s mysterious deaths under investigation, June 1, 2017

• Another mystery in case of Chicago cop couple’s mysterious deaths, June 18, 2017

• Cop drank, drowned in bathtub amid FBI probe of cop husband’s death, July 18, 2017

• Chicago police threw out bloody mattress in mysterious cop death, Aug. 27, 2017

MORE FROM THE WATCHDOGS:

• ‘Criminal sexual abuse,’ other ‘non-index’ crime up on CTA in Chicago

• Trump seeks more tax breaks on Chicago tower with Ald. Ed Burke’s help, Nov. 5, 2017