There are three types of blood draws you’ll routinely see in a DWI case, a hospital blood draw, which is usually performed after a wreck and can be refused, a statutory blood draw, which is typically done with permission by a chemical analyst, and therefore can also be refused, but the third is done according to a warrant after there has already been a willful refusal and cannot be again refused. Once the state has a person’s blood they have to be able to show the chain of custody was unbroken, the blood was stored properly, there was no chance of mix-up at the lab, and that it was properly sealed. All these issues and much more need to be raised in a challenge to a blood draw that results in a DWI.