house on sydney's cove . >> reporter: within minutes of finding nikki's body, police raced to the lyerly homes astounding. the home security system that matt lyerly had casually mentioned to detective emerson a few days earlier appeared more appropriate to ft. knox them a house in the burbs. >> when you first see the house in the road, you can see all of these cameras on the eaves of the house, both sides. >> reporter: there were 21 security cameras in all, with a tricked out control room to monitor and record everything. >> he sounds like a one-man nsa ? >> he was in a very low crime area, so, it almost boggled the mind as to why he felt he needed quite so much surveillance coverage for the house. >> aud to be sure. and observation to take away for later. but the duty that came first. notification. the officers telling matt riley that his missing wife had just been found, dead. >> told me that at one point, seem to get sick. >> matt lyerly may well have been sick of talking to cops, because by now he had lawyered up and was not answering any questions. >> you now have probable cause to get a