"It's great news. They finally got someone after all this time," said Rosaline Horton, 70, of Sherburne in upstate New York on Wednesday.
The body of her 22-year-old son, James Allen Horton, was found, hands tied behind his back with a gunshot wound to the chest, in a ditch near Summerville in Berkeley County in November 1992.
Horton was stationed at Charleston Naval Base at the time. The base closed in the mid-1990s.
Several news outlets reported a Montana man, Andrew Welty of Missoula, a computer systems administrator, was arrested last week after confessing to his role in the death.
Then police in Suffolk County on New York's Long Island on Tuesday arrested a second suspect, Thomas Solheim of Montauk, N.Y.
Prosecutors say Solheim's arraignment had to be postponed Wednesday when the 53-year-old man suffered seizures and was hospitalized. It was not immediately clear whether he has a lawyer.
Both men are being charged in Berkeley County with murder, although warrants had not been served as of late Wednesday, said sheriff's department spokesman Dan Moon.
He said it could be several months before either man is returned to South Carolina. Moon would not comment on a possible motive in the case.
Police in Montana referred calls to Naval Criminal Investigative Service agent Stan Garland in Charleston who did not immediately return messages.
Rosaline Horton, a retired school custodian, said her son was a chief aboard a minesweeper and had served two tours in the first Gulf War.
Her son's body was found about two weeks after his disappearance. The sailor received a military funeral in his hometown.
Rosaline Horton said she understood four people are suspected in the killing, although only two have been arrested.