He came to L.A. for treatment. His body was found in a lake. What went wrong?

Kyle Sherwood flew to Los Angeles in early May for an intensive drug treatment program, his family hopeful that this one might stick. The facility, Dream Center, had come highly recommended from friends in their home state of Washington, and they were optimistic that a fresh start might be just what the 28-year-old needed.

“We were hoping that him being in a different city, a different state, he wouldn’t be able to leave and find his old friends," his older sister Heather Knaack said.

But nothing went according to plan.

Within a few days of arriving in Los Angeles, Sherwood had left the treatment program and called home, using a borrowed phone, from MacArthur Park, a downtown-adjacent square of greenery and open water that has become known for a large homeless encampment. His mom, Deedee Harris, said she tried to convince her youngest son to find his way back to the treatment center, to no avail. She never heard from him again.

Within weeks, Sherwood, 28, was found dead, face-down in the park's lake, according to officials. The cause of his death is under investigation, according to the Los Angeles County Medical Examiner, but police officials said video from the park showed two men pushing Sherwood into the water.

Read more: Police seek suspects who pushed homeless man into MacArthur Park Lake, killing him

Two people were arrested Thursday, according to LAPD Officer Rosario Cervantes, a spokesperson for the department. She declined to provide details.

It wasn't clear on what charges the two were arrested; however, an LAPD spokesperson previously said Sherwood's death was being investigated as a possible homicide.

Detectives told Harris that one of the men arrested had kicked her son in the head before he was dragged into the lake. Relatives said Sherwood knew how to swim.

While Sherwood had struggled with addiction and substance abuse for almost five years, he had always checked in every few days, according to Harris, who called him a "mama's boy." She said she knew something was wrong when she didn't hear from him for almost two weeks.

“I’m waiting for him to call me,” Harris said, recalling her anxiety over the last few weeks. "This is not like Kyle.”

At the end of May, she said, she tried several times to file a missing person's report with the LAPD, both directly and with the help of her son's treatment program. Each time, she said, she ran into a bureaucratic roadblock.

Read more: How L.A. County is trying to remake addiction treatment — no more 'business as usual'

Cervantes, the LAPD spokesperson, declined to comment on the family's struggle to file a missing person's report.

The report might have helped, Harris said.

“That’s their job to go check on them, and they didn’t," she said. "They failed my son."

Despite the questions around Sherwood's death, Harris is trying to figure out a way to celebrate her son's life. She and Knaack remembered Sherwood as the baby of the family, the one who many in their town of Eatonville, Wash., had admired.

“He was a good kid; everybody loved him,” Harris said.

Sherwood was the only one of Harris' six kids to graduate from high school, she said. A successful high school wrestler, he went on to be a reliable union worker in sheet metal, Knaack said. He was an outdoorsman who enjoyed hunting and fishing and a father, raising his 6-year-old son with Harris' help.

But about five years ago, he started getting into drugs — first cocaine, then meth and, more recently, fentanyl pills, Harris said — and struggled to stay sober, trying several treatment programs over the years.

“It’s been a battle," Knaack said.

While the family is glad that arrests were made, they want those responsible for his death to be held accountable.

“They killed him," Knaack said. "I really hope that they don’t make excuses and get off this.”

The family isn't sure how they'll move forward.

“You send your child there to get clean, and he has a 6-year-old little boy waiting for his dad to get back, and I have to tell him he’s never coming back," Harris said. “It’s sickening. ... He’s been trying to do everything he can do to get his life back in order."

Staff writer Summer Lin contributed to this report.

Sign up for Essential California for news, features and recommendations from the L.A. Times and beyond in your inbox six days a week.

This story originally appeared in Los Angeles Times.