The Last Policeman by Ben H. Winters

In a world teetering on the brink of apocalypse, with an asteroid hurtling towards Earth, Detective Hank Palace remains committed to his duty amidst the chaos. As society unravels and people abandon their responsibilities, Hank is determined to solve what appears to be a routine suicide case, convinced it is actually a murder. His relentless pursuit of truth and justice in the face of impending doom highlights the enduring human spirit and the moral dilemmas faced when the end seems inevitable.