Certainly the blitz (dozens of stab wounds in a short time) is his method. However, for a reason which appears never to have been determined, both his known murders were of women with their young children there at the time (who were physically untouched). They were also 20-25 years younger than Penny Bell.

Also, the killer in this case took huge risks with location - the killing was in a public car park with only hedges and the fact (which I can attest to - a friend has two) that Jaguars have excellent soundproofing concealing what was going on. Napper's murders were less risky.

So that Napper was involved certainly cannot be ruled out but, I feel, it is relatively unlikely.