How did Terry Nichols get caught?

Terry Nichols was caught in connection with the Oklahoma City bombing after investigators traced evidence back to him through his association with Timothy McVeigh, the bombing's mastermind. Nichols was identified due to his involvement in planning the attack and was found to have purchased materials used in the bombing. Additionally, witnesses and his own admissions during investigations contributed to his arrest. Ultimately, Nichols was convicted for his role in the attack that killed 168 people.