There was a Down Syndrome young man killed by cop in Maryland recently -- they held him down to the point of suffocating him while he yelled for his "Mommy" because he couldn't understand having to leave the movie theater with his caregiver when the movie ended. A killin' offense? Hardly.
Handcuffs, perhaps?
Having worked as a psychiatric orderly, I can tell you that there are plenty of very effective methods for restraint through physical and pharmaceutical means.
Law enforcement, however, is trained to incapacitate, not to restrain, people who are resisting them.
As an orderly, we were bound by health care standards to “do no harm,” and as such, we were trained to retreat from a patient who was capable of overpowering us.
Cops do not have the ability to discern if a person is intent on doing harm to themselves, others, or the officer himself. I worked in a closed environment where our patients were diagnosed as psychologically unstable. When a cop comes across someone who is “armed” or combative, they are trained to restrain that person, often through the use of cuffs, and ask questions later. If that person is high on drugs, psychologically unstable, or possesses more physical strength than the officer, they’re going to go to extraordinary means to stop that person, even if it means that person exhausts all of their strength and dies in the process.