The announcement came Monday afternoon by police and the city's mayor and city manager.
"After 3 and a half years we are seeing the end of our active phase of the investigation," says City Manger Wayne Pyle.
Police had one final search for Susan's remains last week near Salem Oregon but it turned out to be a dead end.
Throughout the course of the investigation police followed countless tips but they proved to be dead ends.
"At this point we believe Josh Powell was involved," says Deputy Chief Mike Powell.,
But police can't say what his role was in the death of his wife Susan.
Police also say Josh's brother, Mike helped out. Mike committed suicide in Minneapolis Minn. But again, police don't have enough evidence to say what his role was.
In Oregon, police found DNA in the trunk of Mike's car but the trail went cold.
"That DNA did not match that of Susan Powell," says Deputy Chief Phil Quinlan.
At Josh and Susan's home, they also found samples of blood on a carpet. another dead end.
"You have to remember Susan lived there and it could have happened at any time," says Deputy Chief Powell.
Powell also said they used wiretaps between Josh and Steven Powell, his father. But there was never any communications between the two that could be considered as evidence. He also said emails between Josh and Mike lead them nowhere.
"The messages were enrypted," says Deputy Chief Quinlan.
Police also released nearly three thousand pages of documents that they accumulated during their three and a half years of investigating.
They also enclosed crime scene photos. One example was a picture taken of the living room of Josh and Susan Powell.
That's where police say they find small samples of blood on the carpet and there was also a fan that was blowing.
Police say the fan was blowing in a different direction and not in the area where they found blood samples.
Police also released voicemails and police reports amassed during the three and a half year investigation.
In the end all police had was circumstantial evidence, but it not enought for two district attorneys to file charges.
"No body, no crime scene no charges," says Deputy Mike Powell.
He did say they will continue to take any tips or information from the public but will no longer be actively looking for Susan Cox Powell.
Meanwhile, Chuck Cox has told reporters he plans to return to the farm where police were last week near Salem Oregon. He has called for volunteers to help him search the area.