Her body was found after police were called to conduct a wellness check.
Harris, 31, had claimed he killed the model after she refused to pay for an ounce of cocaine.
An autopsy subsequently confirmed that Kraft had been strangled.
Upon returning, Harris said the pair drank several bottles of wine and had consensual sex.
Detectives spent much of Thursday combing the Ardmore condo and the complex for evidence.
He said he had been unable to enter the apartment — which he owns — because the dead bolt had been locked from inside.