Qualia～クオリア～

One one of summer vacation days main character receives an e-mail from his student inviting him to visit a certain small town. He arrives to a wealthy house. Strange murders start to happen with corpses being found on the streets. The town burns up with paranoia, and protagonist becomes one of the main suspects. He will have to take some important decisions which is a matter of life and death.

[From vndbreview]