SEATTLE (AP) -- The women's bodies began turning up in the early 1980s, dozens of prostitutes found strangled near a seedy strip along the Green River south of Seattle.

For over a decade, the case remained one of the nation's deadliest unsolved serial killings; 49 women were either dead or missing, and officials had no solid proof linking anyone to the killings. Then on Friday, 17 years after the first victim's death, police announced a break in the case.

Gary Leon Ridgway, 52, a longtime suspect, was arrested as he left work at a Seattle-area truck company for investigation of homicide in the deaths of four of the women.

"I cannot say with certainty that Gary Ridgway is responsible for all of those deaths ... but boy, have we made one giant step forward," King County Sheriff Dave Reichert said Friday.

Using new DNA technology, detectives had matched saliva samples taken from Ridgway back in 1987 to three victims of the Green River killer, and other evidence had been found linking Ridgway to the fourth killing, Reichert said.

Late Friday, detectives were searching Ridgway's home in a middle-class neighborhood about 20 miles south of Seattle, and they were re-searching a house in Kent where he had lived in the 1980s.

A message left at a phone number listed for a Gary Ridgway was not returned Friday.

An initial court appearance was scheduled for Saturday, though a prosecutor's spokesman said no decision on charges would be made until early next week. Todd Gruenhagen was appointed as Ridgway's lawyer.

Ridgway is being investigated in the deaths of Opal Mills, Marcia Chapman and Cynthia Hinds, whose bodies were found in the river on Aug. 15, 1982, and Carol Christensen, found May 8, 1983, in woods in nearby Maple Valley. Hinds and Mills were both teen-agers. Christensen was 21 and Chapman was 31.

"We're just glad that after 17 years they caught him," Robert Christensen, Carol's brother-in-law, told KOMO-TV. "We miss her."

The break came this spring when forensic scientists were able to link Ridgway's DNA to Mills, Chapman and Hinds, the sheriff said.

Ridgway had been identified as a suspect as early as 1984. He had been questioned after witnesses identified his pickup truck and said he had been seen with two of the victims, according to a 1987 court document.

During a 1987 interview with investigators, Ridgway complied with a court order to chew on a piece of gauze to collect a saliva sample.

"At that point, we just sat back and hoped the technology would get better -- and it has," Sheriff's spokesman Sgt. John Urquhart said.

In March, the department decided to test the saliva again. The successful results came back two months ago, and detectives put Ridgway under surveillance.

Ridgway, who is married and has an adult son, has worked for Kenworth Truck Co. as a truck painter for 32 years. He also has been the subject of intensive background investigation for over a decade. And investigators said Friday that they are looking into potential connections to other unsolved killings.

In 1987, when detectives removed boxes of evidence from Ridgway's home, the search warrant affidavit was largely blacked out on the order of a judge, but the remaining information details two eyewitness accounts linking Ridgway to two Green River victims.

In one case, the affidavit said, one of the women got into a dark-colored pickup truck. The Seattle Times reported in 1987 that the woman was Marie Malvar, and that her boyfriend had tried to follow the pickup. He provided police with the license plate number, but an investigator who knew Ridgway cleared him as a suspect. Later, King County detectives began to focus on him again.

Reichert was one of the original detectives on the Green River killer task force and has made it a priority for almost 20 years.

"I always felt that Gary Ridgway was one of the top five suspects," Reichert said Friday. "This has got to be one of the most exciting days in my entire career."

Ridgway has been arrested twice in the past 19 years, Reichert said -- in 1982 for soliciting prostitution and earlier this month, when he was arrested for loitering for the purpose of soliciting prostitution. He pleaded guilty in the recent case and was convicted in the earlier case, Urquhart said.

The victims whose deaths were attributed to the Green River killer -- mainly young prostitutes and runaways taken from a red-light district south of the city -- disappeared or were found dead from 1982 through 1984.

While authorities have questioned other suspects and made at least one arrest, in 1982, no one has ever been charged in the slayings.