CRYSTAL — Police on Monday arrested the father of a 10-year-old boy who had been missing for nearly a month before his body was found in the Mississippi River over the weekend.

Pierre Collins was arrested on suspicion of second-degree murder in the death of Barway Collins, Crystal Police Chief Stephanie K. Revering said in a news release. The Hennepin County Jail online inmate roster listed Pierre Collins, 33, in custody Monday afternoon.

The Hennepin County Attorney’s office received the case from police on Monday, said Chuck Laszewski, a spokesman for the prosecutor’s office. Charges could be filed as soon as Tuesday afternoon, he said.

Pierre Collins has said he is innocent. A message left by The Associated Press on his home telephone Monday for comment was not immediately returned.

Volunteers had helped search for the missing fourth-grader in recent weeks. His body was found Saturday by searchers from a Boy Scout troop, who then notified authorities.

Officials said the body was discovered about 10 feet from the river’s edge in Brooklyn Center. Revering said authorities have electronic evidence that shows Pierre Collins was in that area of the river at the time the boy disappeared.

Barway was last seen after school on March 18. Video surveillance from his apartment complex shows he was about to go inside, but then turned around as if he was called over to the parking lot by someone he knew, and he walked away, police said last month.

Video from a school van shows that right before he was dropped off, he had said that he saw his dad and a man who he referred to as his “uncle” nearby.

The Hennepin County Medical Examiner has said the cause and manner of Barway’s death are still being investigated.

Barway Collins’ school, Evergreen Park World Cultures Community School in Brooklyn Center, sent a letter to students’ parents and guardians about Barway’s death.

Principal Sheryl Ray said she remembers Barway as a “very friendly student” with “a broad smile” and many friends. On the last day he was seen alive, Barway held the door open for students leaving school before he got on the van, Ray said.