Dreams, they would still have to have a specific reason to draw blood.....“clear indication” that incriminating evidence will be found. There was none.
Wrongamondo......for five years lower courts have allowed blood draw screenings including DNA from blood or swab which the Supreme Court just affirmed. No probable cause needed once a person is arrested, and the courts logic is the small inconvenience justifies the benefits, and allows jails to know the health status of their arrestees who will be staying in the jail, and the Supremes argued it was much like fingerprinting and not a violation of the person under arrest fourth and fifth amendment rights. They are taking blood, and they have been doing swabs under 20 plus state laws mostly for felony arrest. The example I gave you was just three weeks ago where a court ordered a blood draw. The driver had no alcohol on his breath and simply said he did not feel good and asked the officers to call an ambulance. The officers knew this person was not drunk, and he clearly was having a mental health melt down with no indication of impairment, but arrested him and got the blood draw warrant. An officer does not have to lie, and the Courts have made this easier and easier. Zimmerman should have been arrested on a Felony that night on Assault with a deadly weapon, and a whole series of questions should have been asked which were not asked. If the police are going to be chilled to the point they are not going to do normal investigatory procedures and charge accordingly, then relevant evidence will not be collected and folks who shoot people will walk out of jail.
Again, historically a person claiming self defense had the burden at the time of charging to shift the presumption. Currently with Stand your ground the State is in the odd position of having to rebut the self defense before charging. Some self defense cases are clear and the presumption with or without stand your ground does not matter. This was not one of those cases. The delay and sloppy investigative procedures from the officers interviewing to collection of evidence bordered on gross negligence. The Jury spoke and had reasonable doubt.......there should have been no hesitation charging Zimmerman with assault with a deadly weapon immediately, and upgrading the charges later.