I got Harkness in a lunch box in my Fallout Shelter game.
He came with an infiltrator, not a sick plasma rifle like the one he's known for. This seems odd.
Is there any association between Harkness and the Infiltrator, or any assault rifle for that matter, in Fallout lore? This could be in game, or in associated media.
Best Answer
In the inventory section of the Harkness page on the the Fallout Wikia, it lists the Chinese Assault Rifle as his weapon, not the plasma rifle.
There is also a screenshot, which appears to show such an assault rifle on his back.
So, although Harkness may have used his plasma rifle as his primary weapon in the past, it is not the weapon he is using by the time we meet him in Rivet City.
As far as him using an Infiltrator in Fallout Shelter, it is worth noting that there is no Chinese Assault Rifle in Fallout Shelter, and that the Infiltrator is simply the best version of the assault rifle in that game.