Kansas police say they have caught a US serial killer known as the BTK - "Bind, Torture, Kill" - strangler.
Dennis Rader is listed as a municipal worker in Park City
Dennis Rader was arrested without incident in Park City on Friday and is now suspected of committing 10 murders, police in nearby Wichita said.
Charges are yet to be brought in the case, which had been thought to consist of eight murders from 1974 to 1986.
"The bottom line: BTK is arrested," Police Chief Norman Williams told a news conference where he was applauded.
The suspect's DNA has been linked to at least one murder, officials said.
Tips from public
BTK resurfaced last year when a claim was made for an eighth victim.
SUSPECTED BTK VICTIMS
Marine Hedge, 53
Delores "Dee" Davis, 62
Joseph Otero, 38, his wife, Julie, 34, and their two children
Kathryn Bright, 21
Shirley Vian, 24
Nancy Fox, 25
Vicki Wegerle, 28 (pictured)
The Wichita Eagle newspaper received a letter in March enclosing photos and a copy of a driver's licence of Vicki Wegerle, whose 1986 murder was never solved.
Other letters to media and police followed, some including jewellery that police believed may have been taken from BTK victims.
Tips from the public began to pour in and Kansas police took hundreds of DNA samples.
Families of BTK victims and Kansas government officials also attended Saturday's news conference where the arrest was announced.
Chief Williams said that work on the case had brought the victim toll to 10.
The two additional victims were named as Marine Hedge, 53, and Delores "Dee" Davis, 62.
Mayor Carlos Mayans said police had phoned him late on Friday evening to say the DNA of the suspect matched evidence gathered from the scene of at least one BTK murder.
It had, he said, been a "long journey" and he put the arrest down to "diligence, tenacity, determination and just plain good police work".
The BTK killer coined his own nickname in letters claiming the murders.
Most of the victims were women killed in their homes but the first murder attributed to the BTK killer was that of an entire family in January 1974: Joseph Otero, 38, his wife, Julie, 34, and their two children.
Mr Rader is listed by Park City's website as a compliance supervisor, dealing with such things as animal control and broken-down cars.