TAMPA — Days after Bill Denham was found fatally beaten on a Seminole Heights sidewalk in January 2017, at least five witnesses named three suspects in the attack on the 53-year-old social worker as he walked home from the store.

Four months later, police arrested Jadian Zeiders on a murder charge. But the two years that followed saw no more arrests.

The lack of progress grew unbearable for Dan Kane, Denham's partner of more than three decades. Kane attended each of Zeiders' court hearings. He repeatedly voiced his anger to the prosecutor.

"If this was a member of your family," he asked, "would you feel you had done everything you could do?"

Then, two months ago, came a written confession — and last week, a new arrest.

Stephen Mitchell, 34, long suspected as the main aggressor in Denham's death, was jailed Thursday on a second-degree murder charge.

The Hillsborough State Attorney's Office said the charge against Mitchell was based on the "totality of evidence." Kane said Monday a letter suspect Zeiders filed in court may have helped secure the case against him.

Zeiders, 28 agreed to plead guilty in January. With her plea, she submitted a handwritten account of what she says led to Denham's death. She identified Mitchell, who was her former boyfriend, and another man, who has not been charged.

She also dispelled the motive once given in the deadly attack — that Denham had exposed himself to her. It was a notion that many who knew the openly gay man dismissed as absurd.

According to Zeiders' account, she and Mitchell and a second man gathered the night of Jan. 14, 2017, at a house on Escort Avenue, a few yards east of N 15th Street. Sometime that night, Mitchell and his companion left to visit a friend, Zeiders wrote. She was cheating on Mitchell with another man, she wrote, and phoned the man shortly after Mitchell and his companion left.

Zeiders and her secret boyfriend were in the backyard when they heard Mitchell's car pull up unexpectedly, she wrote. She told the boyfriend to hop a rear fence before Mitchell entered the yard.

"Stephen hears some noise by the back fence," she wrote. "He asks me what was I doing. I told him that a guy came into the yard and was masterbating (sic). ... I only told him there was a man in the yard doing that because I was scared that he saw my friend and what I was really doing."

Zeiders, Mitchell and Mitchell's companion left the yard and headed down the street in search of the person Zeiders said she had seen. Near the corner of 15th and Elm Streets, they encountered Denham, who was heading home after buying some frozen dinners at Walmart.

They asked what he was doing in the yard, Zeiders wrote. Denham denied he had been there. Mitchell then attacked him, according to Zeiders.

"I kicked the guy a couple times," she wrote, "only because I was high on drugs and scared of what Stephen would do to me if I didn't back up the story I told him."

Mitchell kept beating Denham as he fell, Zeiders wrote. She yelled at him to stop. Denham got up and tried to walk away. Mitchell attacked him again, she said.

Zeiders said she flagged down a neighbor in a passing truck and told him to call the police. She said Mitchell and the other man pulled Denham onto the sidewalk so he wouldn't get hit by a car. She said she didn't know he was dead until the next day, when homicide detectives came by to question everyone.

"I didn't tell them the truth because I was deathly terrified of my boyfriend," she wrote. "He said if I told them anything , he would beat me until I turned blue."

Zeiders still awaits sentencing. Mitchell was being held in jail Monday on $40,000 bail.

Kane, Denham's partner, said it's his understanding that the state plans to use Zeiders' account and the testimony of Mitchell's companion to prove their case against Mitchell.

"I don't like that," Kane said. "But I can live with it."

The arrest doesn't bring much relief, he said. The pace of the case still frustrates him. And he still grieves his loss.

"It's still something that I deal with every day."

Contact Dan Sullivan at dsullivan@tampabay.com or (813) 226-3386. Follow @TimesDan.