Nearly five decades after an altar boy was found dead in a Massachusetts river, the district attorney says the case is closed. Danny Croteau, 13, was found dead along the Chicopee River in Springfield on April 15, 1972. He had been bludgeoned to death. Former Catholic priest Richard R. Lavigne was named as a suspect in the case but never charged. He died Friday, Hampden District Attorney Anthony D. Gulluni said."In fact, earlier that day, I authorized members of my office's state police detective unit to present the facts of our investigation to a magistrate in order to obtain a complaint and arrest warrant for Richard Lavigne," Gulluni said. "Regrettably, due to Lavigne's death, there will be no prosecution or trial. But, due to the credible and significant evidence that has been assembled in the last year that incriminates Richard Lavigne, I am announcing today that the investigation into the murder of Danny Croteau is now officially closed."Lavigne, a convicted child molester, was the prime suspect for years but his attorneys repeatedly denied any involvement. He was a priest for Croteau's parish and had a relationship with the family.Joe Croteau, Danny's brother, said his family is disappointed that Lavigne will not be brought to justice, but believe "there's a higher power and he will face that higher power now."Gulluni said that investigators began to focus on Lavigne because of the "inconsistent and unusual" statements he made after the murder and because they learned he had lied about the last time he saw Croteau.The DA said Lavigne also showed a typed, unsigned letter about the murder to an acquaintance in 2004. The acquaintance documented the conversations about the letter in emails to superiors at the Springfield Diocese, but investigators did not become aware of the messages until they were handed over in another case. When investigators obtained a search warrant for the letter, Gulluni said his office retained an expert to compare it to samples of Lavigne's known writing. The DA said that forensic linguistics review determined Lavigne could have written the letter. Gulluni said he also authorized investigators to conduct a series of interviews with the former priest earlier this year. Those conversations were recorded during 11 hours of interviews over five days."Lavigne refused to affirmatively admit that he killed Danny Croteau. Lavigne at times was cagy and evasive, continuing his long-running attempts to mislead and distract investigators," Gulluni said. "However, he made several statements to indicate that he was the last person to see Danny Croteau alive — that he brought him to the riverbank on April 14, 1972, that he physically assaulted him there and after leaving Danny there, in his words, and returning a short time later, that he saw Danny floating face-down in the river. He stated further that he neither attempted to rescue him nor alert Danny's parents or police of Danny's whereabouts of conditions."Bishop William Byrne of the Diocese of Springfield issued a statement thanking Gulluni and the investigative staff for their work and extending an apology to the Croteau family. "I was angered and sickened to hear Lavigne's unapologetic admissions in the heinous murder of this innocent child," Byrne said. "It is incredibly disheartening to learn that a priest, a person ordained to care for God's people, would have committed such an evil crime and then not taken responsibility for his actions." Lavigne, who died at age 80, was convicted in 1992 of two counts of indecent assault and battery on a child under age 14, according to the Sex Offender Registry Board. He was classified as a Level 3 sex offender, sentenced to 10 years' probation and seven months of mandatory sex-offender counseling. He was defrocked in 2003.