MEMPHIS, TN (WMC-TV) - Authorities say we may never know what caused a Shelby County couple to die inside their home.
The Shelby County Medical Examiner released their autopsy reports Monday, but the reports leave the case in a shroud of mystery.
Charles Lowry, 61, and Sherry Lowry, 60, were dead inside this home for weeks, yet no one noticed.
Neighbors say they had last seen the couple two to five weeks before their bodies were found.
The Sheriff's Department went to the house last month, after they received a call from Charles Lowry's brother.
When deputies went inside they found the man and woman on their living room couch, badly decomposed.
Their dog was also dead, possibly of starvation. The Sheriff's Department says there were no signs of foul play.
No gun or knife were found at the scene, and there was no sign of a break-in.
Investigators' only hope of finding out what happened was in their autopsy reports, but the Shelby County Medical Examiner's Office says it couldn't determine their causes of death, because their bodies were too badly decomposed.
At the time of the autopsy, Charles Lowry only weighed 68 pounds, and Sherry Lowry only weighed 26 pounds. Charles Lowery's lungs were non-existent.
A doctor did not find signs of severe injuries on either of their remains. A limited toxicology test on Charles Lowry came back negative for drugs that could still be screened. Sherry Lowry was too badly decomposed for toxicology tests.
Neighbor Sylvester McKinley says their deaths just don't add up.
"It's kind of coincidental both of them died at the same time," he said.
While the case is now closed, there is little closure.
For three months in a row, three older couples have mysteriously died.
We now know what happened in each of the cases except this September case.
In August, investigators say a Walls, Mississippi woman intentionally set a fire to kill her husband. Both died from the fire.
This month, a Whitehaven husband and wife were both dead in their home with gunshot wounds. Memphis Police have now ruled their deaths a murder-suicide.