Or just take an ordinary attorney and TMS him...

Agreed, it suppresses electrical activity in the brain, a sufficiently powerful pulse from a device like this can potentially stop all electrical activity in the brain, including the areas that control the lungs and heart.

In theory any sufficiently powerful EM field could kill a person. However it's fortunate that magnetic fields diminish significantly with distance, so the primitive parts of our brain that control bodily functions are relatively protected so I wouldn't be surprised if they start researching ways to use this as a stun weapon.