This is an attempt to make death penalty sentences less random, and to allow a level of nuance to be considered in a very complex and highly emotional decision.
However, these factors are not considered only when the death penalty is on the table.
An attorney may introduce them into any trial where they are relevant.
Mitigating factors are variables related to the defendant or the crime that may persuade a jury to choose a lesser sentence.
For example, if the juror is very young, the jury may decide that he or she is not emotionally mature enough to be held fully accountable for his or her actions, or that he or she deserves another chance in life.
Different states allow different circumstances to be considered as mitigating factors.
In California, there are many such variables that juries may consider as they are deciding on a sentence.
If the defendant acted under extreme stress or control of another person, if the victim participated in homicidal conduct with the defendant, if the defendant has no prior history of violent or illegal behavior, any of these may persuade a jury to choose a lesser conviction or a lighter sentence.
Aggravating factors, on the other hand, are used to persuade the jury that a more serious conviction and a harsher punishment are needed.
If the defendant has a substantial, recorded history of illegal or violent behavior, or if circumstances make the crime especially shocking or upsetting, juries may be persuaded to fight the defendant guilty of the highest charge, and support the strictest punishment.
In the past, mental or emotional illness has sometimes been presented by defense attorneys as a mitigating factor.
The argument is usually that the defendant could not understand the consequences of their actions, or was under extreme emotional distress at the time of the incident, and therefore should not be considered fully accountable.
The success of this defense depends heavily on the type of crime being discussed, the persuasiveness of the defendant and the jury in question.
In the 199 California case of People vs.
Gregory Smith, this type of argument took on a very controversial new twist: prosecutors in that case used mental illness as an aggravating factor.
Their expert witness, Dr.
Chris Hatcher, explained that Smith had a serious disorder known as sadistic pedophilia and therefore was very likely to reoffend.
Although many people protested, the state Supreme Court upheld the prosecution's right to make this argument.
For more information about criminal trials and mitigating or aggravating circumstances, contact Appleton criminal defense lawyers Kohler, Hart & Priebe.