Who did sam westing frame of killing him?

I honostly think it was SyDELLe Pulaski.

Evidence

1. Is the two unfortunate fellows in the beginning had blood on there hands yeling "Purple Waves!"

2.Turtle thinks of "Purple Waves" when she stares at SyDELLe Pulaski's dress.

3. SyDELLe Pulaski seemed to be worried after the will of Mr. Westing was stolen from her notebook.