In a July 20 letter to the man's brothers, Bennett said he personally reviewed the files and interviewed an unnamed key witness before deciding against attempting extradition and prosecution of a suspect in the crime.

The letter was released by Kurt Mausert, a lawyer in upstate New York whose brother, Eric Mausert, was stabbed in the heart on a Honolulu street while accompanying a young couple from his Hare Krishna temple to the airport. Eric Mausert died Feb. 22, 1979.

Juvenal Llaneza, the brother of the woman who was with Mausert, was jailed after the stabbing, but released after 48 hours. He then apparently left the country by the time he was indicted for manslaughter several months later.

Kurt Mausert and his brother Mark, both lawyers, have tenaciously lobbied prosecutors in Hawai'i for more than a decade to take up the cold case. Mausert said he located Llaneza in the Philippines with a Google search.

Honolulu prosecutors in 2005 transferred the case to the state attorney general's cold-case unit.

"My decision was based upon the fact that I do not believe we can prove Mr. Llaneza's guilt beyond a reasonable doubt," Bennett wrote in the letter to the Mausert brothers.

The letter effectively ends chances of a prosecution by state or local officials in Hawai'i. Kurt Mausert today said he will pursue the case with federal prosecutors.