Amorality refers to moral neutrality, or having no moral implications. It is not to be confused with immorality which means the violation of morality.
An amoral person can also mean a person without a conscience or without a moral code. Such people are rare. See Sociopath. People are sometimes wrongly accused of amorality when the accuser has a different moral code.
Amoral people can live good, lives, as well as be beneficial to others, if they act out of enlightened self-interest. Still you can never trust amoral people because they can at any time decide it's in their interest to harm you and moral principles won't stop them.
If amoral people do not act out of enlightened self-interest, and arbitrarily act like a jerk, amoral people become unhappy because nobody respects them. They don’t respect themselves.