From Wikipedia: Witchcraft Laws

I've been doing some digging into the Salem Witch Trials. Here's a look at the laws they were based upon. I'll add more history a I come across it.

- Click here for the entry. 

As I read it, the Salem trials appear to have been conducted under those passed in 1604.

In 1604, the year following James I's accession to the English throne, the Elizabethan Act was broadened by Edward Coke and others to bring the penalty of death without benefit of clergy to any one who invoked evil spirits or communed with familiar spirits. The Act's full title was An Act against Conjuration, Witchcraft and dealing with evil and wicked spirits, (1 Ja. I c. 12).[9] It was this statute that was enforced by Matthew Hopkins, the self-styled Witch-Finder General.

Supporters of the Act included the Earl of Northumberland, the Bishop of Lincoln, the Chief Justice of the Court of Common Pleas, the Attorney General for England and Wales, the Lord Chief Baron of the Exchequer, and the Chief Justice of the King's Bench.

The Acts of Elizabeth and James changed the law of witchcraft by making it a felony, thus removing the accused from the jurisdiction of the ecclesiastical courts to the courts of common law. This provided, at least, that the accused persons theoretically enjoyed the benefits of ordinary criminal procedure. Burning at the stake was eliminated except in cases of witchcraft that were also petty treason; most convicted were hanged instead. Any witch who had committed a minor witchcraft offence (punishable by one year in prison) and was accused and found guilty a second time was sentenced to death.