David Wiley pleaded guilty to second-degree reckless endangerment in the deaths last April of Joan and Richard Gilman.
Wiley was the caretaker at the property where the Gilmans died of carbon monoxide poisoning. Prosecutors say he was running a generator in a garage under their bedroom after their electricity was shut off.
Wiley was initially charged with criminally negligent homicide, but prosecutors say he had left a door ajar to allow the fumes to dissipate. He is expected to be sentenced to nine months in jail.