Makes sense except that he was being watched closely right after it was noticed she was missing, and she was noticed missing very quickly. It would have been a huge risk for DSjr to return to deal with her body. Not impossible, but a risk for him nonetheless.
Of course, he could have dealt with the body at some time during the night, especially if the twins stayed at Sr's that night. Do we know where the twins were the night of the 17th? DSjr had purportedly taken them to Sr's house that afternoon but did they stay the night there or return to the condo?