CONCORD, N.H. — A 10-year-old Massachusetts boy who disappeared in the White Mountains in 2003 died of hypothermia, not from foul play as his family believes, New Hampshire’s U.S. attorney said Tuesday.

A monthslong independent investigation with the FBI ruled out suffocation and other suspicious causes in the death of Patric McCarthy of Bourne, Mass, said U.S. Attorney John Kacavas. Patric was on vacation with his family in Lincoln over Columbus Day weekend in 2003 when he apparently got lost racing his stepbrothers home.

His body was found four days later more than 2 miles from his family’s condo.

Kacavas told The Associated Press on Tuesday that he rejects the family’s assertions that Patric was strangled or suffocated. He said Patric’s body had no evidence of trauma and called work by the family’s private investigators “reckless” and “shoddy.”

Patric’s father, Stephen McCarthy of Bourne, said he’s “disgusted but not surprised” by Kacavas’ findings.

“I don’t think New Hampshire did any investigating,” McCarthy said. He said his only recourse is “to get them out of office or go higher. I don’t know if we can go any higher.”

Kacavas said the case “tragically has suffered from reckless speculation by a number of people over the course of the last eight years that has led this poor family to believe something untoward happened to Patric. All the credible evidence suggests he died an accidental death due to hypothermia.”

Kacavas said he wrapped up his investigation in December and notified the family in April.

Patric’s parents have said they believe his then-12-year-old stepbrother might have suffocated him. Kacavas said Patric’s body displayed no traumatic or suspicious injuries to support that conclusion.

“The recovery site was 2.2 miles from the site where he was last seen,” Kacavas said. “That would have required a mind-bending logistical arrangement where the 12-year-old is able to identify the location of the body and someone transported it 2.2 miles undetected while some 80 volunteers were searching the area.”

Patric’s mother, Deanne Murray of Buzzards Bay, Mass., said Tuesday that she still believes Patric was killed and began crying uncontrollably. Her mother, Jacqueline Murray, said, “Deanne is so burned out. When you know it’s not an accident, that’s the worst part.”

Attorney General Michael Delaney reopened the case after he took office in 2009. He concluded last year that there was no basis to prosecute anyone in the case.

Deanne Murray told the AP last year that a private investigator assembled accounts from four pathologists who reject hypothermia as the cause of death.

“This is not a hypothermia case,” she said then. “His clothes were never found, hat was never found, his coat was never found. He had bruising on his gumline, he had dirt up his nose, he was straight out in a prone position, he had lesions on his face. I mean come on, it’s ridiculous.”