Russ is on the right track. The flavor is really similar. You have good skills to investigate, and in combat you think up clever ways to weaken foes or blunt their offense, even if you aren't doing the most damage.
Depending on what style of investigator you were interested in, you might takes feats like Arctech Tinkerer | Level Up to use gadgets (btw Russ, any chance we could hyperlink that feat to point to the Gadgeteer fighter archetype?) or maybe Mystical Talent, Physician, or Rite Master.
For me, the thing I loved most about investigators is building on the social and world of the games that I use the class in. I'm not much of a combat person, but even when I am in combat, due to the ability Devise a Stratagem making sure that the investigator doesn't feel useless. I also think the idea of pursuing leads and having to choose carefully between what is important in the now in a campaign and what is important overall is all stuff that is fun to pay attention to and balance out with Pursue a Lead. Finally, my favorite Investigator feat (compared to those two main abilities) happens to be That's Odd - I've found it both compelling for both the players and the DM. It lets something stand out every time the characters move to a different space, and DMs always have the opportunity to put plot hooks and stuff for players to dig their teeth into. Those three really embrace the spirit of the Investigator overall no matter what methodology/archetype you choose.