How can people keep quiet for years?

[Kaley Smith]

One of my relatives kept quiet about seeing a man accused of murder in the hospital dropping off flowers at the time the murder occurred. She knew that other people who had been on the elevator and at the front desk had seen him too. Maybe they would report this to the police, and she wouldn't have to get involved. Maybe she was wrong? But no, he was known to always wear cowboy boots and hat. He stuck out in a crowd. She was sure the suspect was innocent, but everyone, including police, were so convinced the suspect was indeed the killer, and they wanted him locked up for life. Four years later the man was cleared, released and given compensation, but it still haunts my relative to this day that she hadn't said anything.