Carson City, a small town under NCR protection, geographically south of New Reno, serves as a rest and recreation spot for bandit hunters.
Write an announcement on the board
You can get this mission from Mary, the owner of the motel in the north of the "Center" location. Mary at the motel will ask you to post a note on the notice board if you ask her about work. It doesn't give any XP, only $10.
Find the city killer.
The mission can be obtained from the mayor of the city in the building slightly southeast of the center of the "Center" location.
We search for a small house in the east of the location with a pile of rocks in the corner. We clear the rocks, revealing a staircase to the basement. Descending, we discover the body of the missing man. Examining the body will reveal information about strange symbols on the basement walls and a series of letters on cubes near the body. We ask Mary who she associates with this combination of letters, and we come up with three suspects. One is standing to the west of Mary – hotel employee Emil Tao. We speak with him and receive assurances of friendship with the deceased, along with a claim that the deceased paid for the drinks. We verify this information with the bartender, and at the bar, we are brought to tears by the news of the death of a kind old man, a local alcoholic – the second suspect. That leaves the third – the mayor himself. We return to his house and examine his belongings – the bookshelf, the bed, the walls of the restroom – everywhere you look you'll find the same symbols as on the walls of the basement with the corpse. After this, we tell the truth to the mayor (+3500xp), after which we punish the murderer. To see the signs on the wall and in the house, you need a Perception of 7.
There's a bar in the east of the "Center" location; you can buy Nuka-Cola, Beer, and Vodka from the bartender.
There's a funny bug where you can endlessly turn in this quest because the mayor won't attack unless you're standing next to him.
Source: falloutmods.fandom.com.