OK, several years ago a girl reported her Chinese boy friend was kidnapped. Cops were on that immediately. Happily that came to a good ending with the perpetrators now serving very lengthy sentences! Perhaps if the Pickton cases were taken as seriously there may be fewer sad endings today!
I am thinking that perhaps the speed at which the report came in may have been a factor too? I suspect the girl's report was within the first 24 hours if not sooner. The trail would be hot.
With Pickton's victims, how long did it take someone to report them missing? Also, were there any witnesses available that would talk to the cops?
Pickton chose his victims knowing that he would have a huge amount of time before they were missed and any witnesses would not speak to the cops.
The solution to this of course is legalized prostitution so there would be no hiding in alleys. I suspect that a serial killer would have a harder time preying on legal workers than illegal ones.