Insein,
I don't know if it is simply because of your bad experience with the police officers you have encountered, or if you are simply exceptionally wary of authority...but I believe you are (deliberately or unintentionally) overlooking a whole bunch of factors in this event.
The woman was pulled over for a number of infractions. 51 in a 35 is fast. 35 zones are often fairly residential...at 51 miles per hour she is not just speeding, she is pretty darn close to reckless endagerment.
In addition to going almost 20 miles over the posted speed limit , she is driving with a broken windshield, which would hinder her ability to see what was in front of her car...incredibly dangerous.
Her car also has a broken taillight and she is driving without a seatbelt.
Before the police officer knows anything else he knows that she is an irresponsible woman who does not care for her vehicle, her own safety, the safety of others or the laws of the state she is in.
Why does he know this? Because he is a police officer, who has to make snap judgements about people every day in order to stay safe and alive, and keep others safe and alive.
With this in mind, he is already wary as he approaches the car. The woman immediately begins belligerantly...stating that she has done nothing wrong and insinuating that she is being pulled over because the police officer is a racist.
This would send off more warning bells in a police officer's head. The woman is going to state that she has done nothing, when it is perfectly obvious she is guilty of several infractions...and she is going to make it a race issue...which means the police officer knows he has to do everything right...or risk ending up defending himself in court...
So not only does the police officer in question know that this woman is a) a criminal b) a danger to society and herself and c) a liar, he also knows that she is a race-baiter and he must do his job properly.
So he is remarkably polite (as I would expect from any public servant) to this woman as she insults him and ignores him. Count how many times he asks politely for her license and registration...count how many times he politely says "Please shut the door," rather than simply tazering her for making threatening gestures by getting out of her car when she was told not to...he deals with her politely and respectfully throughout their interaction.
He finally gets her information..he POLITELY informs her that she is being pulled over for a myriad of reasons, and then goes to check back at his car...where he finds out..surprise suprise...that not only has she broken the law umpteen times today...but she is also driving with an suspended license.
He returns to the car and asks her to step out of the car...several times. She states that she is going to make a phone call...he asks her several more times to get out of the car. At that point, he pulls out the tazer, announces that if she doesn't get out of the car he will use it...he warns her of this several more times...she is giving information about her location to her boyfriend...from this point until the tazering we can neither see nor here what has happened....
However...
While you immediately jump to the conclusion that the cop tazered her for the sick fun of it...I, who have a bit more faith in the men and women who agree to put themselves in harms way every day for no money, very little respect, and the chance of being killed everyday...see it this way...
Was she grouping around in her bags at all? Was she rummaging for something? Reaching for something? Did she gesture at the cop and that gesture was mistaken as a hostile action?
The cop knows that this woman is a criminal with no regard for the law. He knows that she has been openly hostile to him since the first moment of their interactions...he knows that she knows she is about to be arrested...
If this woman makes a move of attacking him or the other officer...or makes a move that the police officer interprets as going for an unseeable item in the car (for instance, a gun or other weapon)...then that officer has EVERY RIGHT to exercise non-lethal force in tazering her.
Is it pretty? Nope. Her screams are terrible.
Perhaps she should have obeyed the law by not speeding. Not driving with a broken windshield. Not driving with a broken tail light. Not driving without a seatbelt. Perhaps she should have listened to the police officer and complying with his completely legal demands. Perhaps she should have not been driving completely illegally. Not followed the police officers orders when she was being placed under arrest. etc. etc. etc.
What surprises me, Insein, is how unbelievably forgiving you are being to this woman who is so obviously in the wrong in so many ways...while being so unbelievably UNforgiving of the police officer who followed protocol, treated the person with respect, articulated his demands clearly, issued no unreasonable demands, and finally resorted to non-lethal force after requesting the person comply willingly numerous times.
We, as a functioning society, need to have a police force. In order for a police force to function, law abiding citizens (and even the citizens who occassionally commit small infractions like speeding) need to respect those officers who are doing their jobs legitimately and comply with their reasonable requests when they are given.
The police officer in question made nothing but reasonable requests...and he was confronted with nothing but a completely unreasonable woman. While I respect and completely support your desire to monitor those with authority...I think in this case, the officer wielded his authority appropriately given the situation at hand.