I just watched the CIA episode again and IMO, a potential reason that the CSK stopped killing was the police had installed covert and non covert surveillance cameras.
My understanding is that Telstra would have been engaged to install these cameras on behalf of police, and as BE was a Telstra Tech, he may have had knowledge that these cameras were being installed throughout Claremont and the surrounding areas.
Although BE may not have had knowledge of the camera locations, he may have been scared just knowing that cameras were being installed.
Could be on the money but then why not just change locations?
Why was claremont his target area? Must be something about claremont.....