Can police trace a blocked cell call?

Yes they can ! Even if someone blocks their number - it's still registered at the company's equipment. There will still be a record of the call - and where it came from - even though you don't see the number.

^^^^^True

Get a drop phone Mr. Shady. Pre-paid phones are dirt cheap. Even cheaper and more shady would be to get someone else's old gsm phone, or get one from one of those phone recycling boxes they put in grocery stores.. not exactly legal that way just don't get caught. Pre-paid sim cards are like $5 if not free with a $15-$30 initial top up.