In the Needle in a Haystack mission of STALKER 2, you’ll encounter Squint, who has Ward Sensors that are crucial to completing your objective. You have three options to proceed with Squint’s fate: help him escape, kill him, or get the artifact for him and then kill him.
Killing Squint is not a recommended option as it will limit your choices for using the sensors and miss out on the Piece of Cake side quest, which rewards an artifact. Leaving Squint alive allows you to eventually acquire the artifacts he needs, giving you more flexibility in completing the mission.
If you choose to help Squint, you’ll start a side mission called Piece of Cake, where you’ll need to find an artifact in a cave. Be prepared for combat with an invisible bloodsucker and search bodies for healing items and ammo. Once you obtain the Mold artifact, return to Squint, but don’t expect any significant reward, as he only has the Ward Sensors to give.
A more advantageous option is to get the artifact for Squint and then kill him at the last minute, allowing you to loot his gear and the artifact without any repercussions or consequences. This decision will test your attitude towards simulated betrayal and murder in future missions.
Source: https://www.gamesradar.com/games/fps/stalker-2-squint-help-kill