How is Hyde presented as evil in Dr. Jekyll and Mr. Hyde?

Mr. Hyde is presented as evil via a great deal of indirect characterization. Mr. Enfield, for example, describes the way Hyde "'trampled calmly over [a] child's body and left her screaming on the ground. It sounds nothing to hear,'" he says to Mr. Utterson in the first chapter, "'but it was hellish to see. [Hyde] wasn't like a man; [he] was like some damned Juggernaut." Hyde is completely unfazed by the damage he does to the child and seems "'perfectly cool'" in response to Enfield's accusations. In fact, Hyde simply keeps walking even after he stomps right over the little girl. Hyde then gave a look "'so ugly that it brought out the sweat on [Enfield] like running.'" Even the doctor who was brought to examine the child and ascertain the extent of her injuries seemed to "'turn sick and white with the desire to kill'" the man. The women present had to be held back from tearing Hyde apart, and Enfield says that they were "'wild as harpies.'" Enfield declares that he never saw "'a circle of such hateful faces'" as were inspired by Hyde's actions, demeanor, and even simply by his person. Through this indirect characterization, we can gather that Hyde is callous, unfeeling, odious, and—yes—evil.

Mr. Hyde is presented as a throughly wicked individual, without the slightest shred of moral decency. Dr. Jekyll's evil twin is a murderer and a criminal, a beast of a man who hasn't the slightest hesitation in killing anyone who gets in his way. What makes Hyde particularly evil is that there's no rhyme or reason for his crimes. His murder of Sir Danvers Carew is completely senseless; the man has never done any harm to him whatsoever.
Stevenson doesn't go into too much detail regarding Hyde's sordid nighttime activities, but it's clear that whatever he gets up to transgresses the boundaries of what's considered acceptable in Victorian society. Hyde is selfish and lustful, thinking only of himself and his own needs, irrespective of what anyone else might think. Today, psychologists would probably describe him as a sociopath, the kind of scary character you see in countless TV shows and movies where there's a dangerous serial killer on the loose.