MINNEAPOLIS — A Minnesota man admitted Monday that he killed his 10-year-old son, saying he beat the boy in a fit of rage, then wrapped the child with duct tape and threw him in a river because he feared he’d get in trouble.

Pierre Collins, who made public pleas for help after his son went missing in March, detailed the attack after pleading guilty to second-degree intentional murder. He was immediately sentenced to 40 years in prison, the maximum allowed.

“I killed my son,” Collins told the judge as several onlookers wept inside the Minneapolis courtroom. He later said,“I would like for everybody in the community to forgive me.”

Overcome with emotion, Barway’s mother slid out of her chair when she heard Collins admit his guilt.

Their son, Barway, was last seen alive March 18. Surveillance video on that day showed the boy bouncing out of a van as he got dropped off at school, saying, “There’s my dad.”

Collins long insisted he had nothing to do with his son’s disappearance, and hundreds of volunteers helped authorities search for Barway for weeks. His body was found in the Mississippi River by volunteers on April 11, and Collins was arrested two days later.

A woman who helped in the searches, Victoria Peabody, told the judge Monday that she felt broken. She said she visited Collins many times during the searches and he continued to beg for help.

“I just feel so dirty, because I held his hand and prayed for him,” Peabody told Hennepin County District Court Judge Tanya Bransford.

Several people wept openly during the hearing, including Barway’s mother, Louise Karluah, who lives in Liberia and came to the United States for her son’s funeral. Still, she said she has forgiven Collins.

“Killing a child is not right,” she said after the hearing. “So I’m not feeling good right now. I’ve been praying for justice for Barway.”

Surveillance video from his apartment complex on the day he went missing shows Barway walking toward the building’s entrance, but then quickly turning and going another direction.

Under questioning from assistant public defender Shawn Webb, Collins said Barway was supposed to go into the apartment but Collins saw him outside playing and got angry.  Collins said he called his son over to him and started to hit him, then the boy fell to the ground and wasn’t responding.

Collins said he thought he would get in trouble, so instead of seeking help for Barway, Collins put the boy in his car, wrapped duct tape around his arms and legs then put his son in the river.

“You knew that by doing this, your son was going to die,” Webb said.

“Yes,” Collins replied.

Authorities haven’t said whether Barway was still alive when he was placed in the river. The medical examiner’s office said in June he was killed by “unspecified means.”

Hennepin County Attorney Mike Freeman said the exact motive for the killing was still unknown. According to the criminal complaint, Collins was unemployed and had two life insurance policies on his son. Prosecutors said Collins inquired about increasing the coverage on one of those policies just two days before Barway’s disappearance.

As part of the plea agreement, a premeditated first-degree murder charge was dismissed.

Bransford said Collins’ sentence is longer than the standard for second-degree intentional murder because the victim was particularly vulnerable at age 10, Collins was in a position of authority and hiding Barway’s body was particularly cruel.

“It is hard to conceive — unimaginable — that a parent would kill their own child,” the judge said. “Unfortunately, there’s nothing that can ever be done that will bring back Barway Collins.”