On
Distinguish generic aggravating circumstances from qualifying aggravating circumstances.

Generic Aggravating Circumstances
a. affects only the imposition of the penalty prescribed but not the nature of the crime committed;
b. can be offset by ordinary mitigating circumstances;
c. need not be alleged in the information as long as proven during the trial, same shall be considered in imposing the sentence.

Qualifying Aggravating Circumstances
a. must be alleged in the information and proven during trial;
b. cannot be offset by mitigating circumstances;
c. affects the nature of the crime or brings about a penalty higher in degree than that ordinarily prescribed.

Related:

Aggravating Circumstances
Mitigating Circumstances