"We are dedicated to getting justice for these victims - we're absolutely disappointed in the verdict but they did what they could with that they had - they worked really hard," said Deputy County Attorney, Nicole Green.
According to the Prosecution, the couple traveled to Tucson from Phoenix to purchase a motorcycle. Prosecutors says the couple had a passion for vintage motorcycles.
After the couple missed work - a missing persons report was filed. Days later their red Ford F-150 truck was found abandoned in a parking lot of Santa Cruz Catholic Church.
In 2015, investigators cracked the case open after DNA evidence taken from the couple's truck years earlier was linked to Brian Ferry.
"The family is dealing with it but they're also wanting to seek justice for their family members - Chuck and Kathy. They're ready to go at it again - just like we are," said Green.
Police have not found the bodies of either victim.
A status conference is set for February 21 to determine the next trial date.