Underworld Investigator Feat 1
Source Pathfinder Advanced Player's Guide
Your work as an investigator makes you familiar with the criminal element. You might be a criminal yourself, or you might have gained an understanding of how they operate from the outside.
You become trained in Underworld Lore, and you gain your Pursue a Lead circumstance bonus to Thievery checks to investigate the subject of your lead (such as checks to Steal a clue from a suspect or Pick a Lock to open a safe with damning documents).
Traits
Anything that doesn't list another rarity trait (uncommon, rare, or unique) automatically has the common trait. This rarity indicates that an ability, item, or spell is available to all players who meet the prerequisites for it. A creature of this rarity is generally known and can be summoned with the appropriate summon spell.
InvestigatorThis indicates abilities from the investigator class.