If the judge has discretion to determine the sentence, the defense may bring to a judge's attention an infinite number of factual circumstances that may move the judge to impose a lighter sentence. The following are examples of such circumstances (called "mitigating" factors):
- the offender has little or no history of criminal conduct
- the offender was an accessory (helped the main offender) to the crime but was not the main actor
- the offender committed the crime when under great personal stress; for example, had lost a job, was late on rent, and had just been in a car wreck, or
- no one was hurt, and the crime was committed in a manner that was unlikely to have hurt anyone.
Just as mitigating circumstances can sway a judge to lessen a sentence, "aggravating" circumstances can compel a judge to "throw the book at" an offender. A previous record of the same type of offense is the most common aggravating factor. Other aggravating circumstances grow out of the way a crime was committed, as when an offender is particularly cruel to a victim. Sometimes, laws themselves specify aggravating factors, such as the use of a weapon.