Be careful what you read on the Internet (including this blog!). It seems that the police investigating the recent murder spree were led to the suspect via an ad for a motorcycle placed by one of the dead soldiers. The police traced 580 IP addresses that had visited the ad site, and one of them turned out to be the brother of the alleged killer. Another lead involved an inquiry, apparently by the killer himself, to a cycle shop about the possible existence of a GPS geotracker device on his scooter. He wanted to know how to disable it.
The DCRI also had a watch on the alleged assassin because of his two visits to Afghanistan and Pakistan in 2010 and 2011.
Remarkable police work, I think.