The cops missed. The lock down didn't work, he was hiding in the boat outside the lockdown area. Once the martial law was lifted and people went out is when someone saw the blood and called.
"Lock down didn't work". Really? Think again.
NOBODY ELSE DIED. Suspect apprehended. It certainly did some good. The lock down kept the suspect "locked down" where he was, even if just outside the "official perimeter"... he couldn't go anywhere far and with all the bleeding was getting weaker by the hour, hiding out until he couldn't stay hidden longer. He probably would have died in the boat if he hadn't been tracked down, he was so out of it.
So what if a civilian found traces of blood that led to the suspect? The police asked citizens to be vigilant and keep an eye out. They did. They helped.
Yeah, it's easy to sit back in your comfy chair and cite how this was an unreasonable form of marital law, but had they not done this and the suspect managed to kill more people... what then? So people were inconvenienced. Most people would agree that being safe is far worth the trade-off of inconvenience.
Sheesh... get with it.