Why are poisons rarely used in homicides?

Poisons are rarely used in homicides because they can be difficult to administer without detection, and their effects may take time to manifest, allowing for suspicion to arise. Advances in forensic science make it easier to identify toxic substances during autopsies, increasing the likelihood of catching the perpetrator. Additionally, the uncertainty of the poison's effectiveness and the potential for unintended consequences can deter would-be killers from using them.