Payson Police Lt. Don Engler said forensic tests have yielded no clues as to who kidnapped and murdered 56-year-old Ira Eastman in March.
"We are on our second round of evidence down at the Department of Public Safety crime lab," Engler said.
"Our first round did not produce a lot of usable information and no DNA evidence useful to the investigation."
Eastman's wife, Peggy Tepolt, returned from the gym early on the morning of March 15 to find her husband missing.
Signs of a struggle at the home on Luke Drive prompted Payson Police to declare him missing and presumed kidnapped.
Three days later, divers from the Gila County Sheriff's Office discovered Eastman's body in the East Verde River. They were looking for a gun that a 12-year-old Valley boy found and threw back in the water. The boy's mother reported the find to the sheriff's office the following day.
A .22 caliber handgun was later recovered from the murky waters.
"We still are not to the point where we can commit that (the handgun) is the murder weapon because we still don't have the final reports from DPS on the testing that they have been doing for us," Engler said.
The bullets that exited Eastman's body were never recovered from the scene, Engler said, which could have confirmed the gun was the murder weapon.
Engler said he cannot specify what pieces of evidence had been processed due to the ongoing investigation, but said the first round of evidence included items that would provide the best evidence for the case.
Detectives continue to pursue leads, but Engler said physical evidence is powerful.
"Ultimately, it will be a major part in the case," Engler said. "The physical evidence needs to be in place to support our theories."