MINNEAPOLIS to -- A pastor who stood by a Minneapolis man accused of killing his ten-year-old son in March says the man confessed the killing to him three months ago, reports CBS Minnesota.

Pierre Collins long denied any involvement in the death of his son, Barway. But on Monday he formally admitted striking the boy, then binding him with duct tape and tossing him in the Mississippi River near Minneapolis. The child's body was found in April, weeks after he disappeared March 18.

In pleading guilty to second-degree intentional murder, the 33-year-old Collins stated: "I killed my son."

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Pastor Harding Smith held a press conference Tuesday afternoon to announce that Collins had revealed to him on May 8 that he killed the child, according to CBS Minnesota. Smith stood by Pierre during the search for the "missing" boy, and after the body was discovered, reportedly serving as a spokesman for the family.

A grand jury indicted Collins on a first-degree murder charge in June, saying the killing was premeditated. Investigators reportedly said he killed his son for insurance money.

The first-degree murder charge was dropped as a part of his guilty plea, reports the station.

He was given the maximum sentence, 40 years, because the boy was considered vulnerable and because hiding Barway's body was considered particularly cruel.

Collins said he arrived home the day Barway was eventually reported missing and found the boy outside playing, which he was not supposed to be doing because he was supposed to be inside after school, reports CBS Minnesota. He said he hit the boy, who fell to the ground and became unresponsive. He said he was scared of what would happen and took the boy to the river, taped the boy's limbs and threw him in the water, CBS Minnesota reported.

Police said surveillance video and cellphone recordings helped link Collins to the crime scene, reports the station.