DeMartin, of Evesham, was a clothing store executive who was missing for 2 and 1/2 years before her body was found and identified last winter.
Crow, who worked on the groundscrew at DeMartin's Sagemore Drive condo complex, admitted entering through a sliding door. When DeMartin awoke to find him rifling through her purse, he says they struggled and he strangled her.
"She stopped fighting and stopped breathing," Crow said in court.
Crow drove Marianne DeMartin's car to upstate Pennsylvania and dumped her body. He then came back to New Jersey and left the vehicle next to a dumpster behind a convenience store in Vorhees.
Crow was sentenced to 40 years in prison, and has to serve 34 years before being eligible for parole.
When Crow plead guilty, DeMartin's parents said they were sorry New Jersey doesn't have a death penalty.
They said they offered the plea to him so they can get the process over with before they were gone.