Let's assume for a moment that Ricci is the perp.
1.) LE has told us that he is a cat burgler
2.) He possibly had a key to the smart home.
3.) He was very confident going in for the 'job'.
If he had a fixation on Elizabeth and was going to snatch her, a good cat burgler would case the situation. If I were such a perp, I would make at least a couple of dry run's first. I might open the front door on several differant nights to insure that they were not in the habit of turning the alarm on. I would make sure I knew where she slept. On all of these practice runs I would be wearing my "ninja outfit". On the night of the abduction the dark outfit could be a liability once the house had been cleared.
Then again, maybe this thing wasn't that well planned. Maybe Rick just decided on the spur of the moment to go to Federal Heights and grab the object of his fantasies. I hope that is not the case because if so then Elizabeth is surely not with us anymore.