We're talking about Brazil here, not the United States. Brazil does not use an English common law system where court decisions create precedence. To have any real power, laws in civil law countries need to come from legislation.
In theory, yes. In practice judges in Civil Law systems also tend to let themselves be guided by precedent.
(Conversely, in Common Law precedent crumbles before a judge sufficiently motivated to find reasons why the case before her differs enough to warrant a new judgement. Often there are even multiple precedents to choose from, depending on which features of the case you want to emphasise.
Identifying a precedent is like find a metaphor or analogy.)
