Convicted Pickton NOT guilty of premeditated murder?!

I'm relieved that Pickton has been convicted for the murders of six women, but why only guilty in the Second degree? How is it possible that the jury found he committed six unplanned, unpremeditated murders?

Or more specifically, why was the prosecution unable to prove that a man who seeks out, tortures, murders, and disposes of six (and twenty...) women has a very definite PLAN. A plan that includes knowing where to go shopping for future victims, a collection of homemade objects and weapons with which to torture and kill, and a methodical process for disposing of the accumulating bodies.

Pickton is a serial killer; a serial perpetrator of sexual violence. He chose his victims purposefully, he carried out their deaths purposefully and systematically over a period of years. Whether or not the Twenty remaining murdered women will receive a proper trial, isn't six murders enough to convince of his premeditation? To convict in the First degree, and thus secure a life sentence? to secure six life sentences.....?