Supervisor helmet

Location
The Supervisor Helmet is worn by the Pitt Raider outside where Ashur usually stands, he usually wields a sledgehammer, as he is wearing it. The only way to obtain it is by either killing him or reverse-pickpocketing the item with something better, this Editor suggests a Brotherhood Power Helmet. Confirmed on Xbox 360 acquired Reverse Pickpocketing Metal Head Gear (Dam Res only 4). Was taken off the Pitt Raider just before entering Haven building.

It may also just be looted from the hostile Pitt Raiders killed before entering Downtown. Another way to obtain the Supervisor Helmet is to talk to Friday, a vendor in the Downtown section of the Pitt. She will sell you the Supervisor Helmet for about 70 caps but in bad condition so return there every 24 hours until she has another. NOTE: you have to buy or sell something before she get the Supervisor Helmet back in stock.

It is also very possible to find this on the corpse of one of your opponents in the arena fights.