38 Who Saw Murder Didn't Call the Police

Would I call the police if I heard someone getting stabbed to death outside my house? Well, if someone asked me that without saying anything else, I would say yes without hesitation. However, I assume most people would say yes, too. Yet the 38 people who were actually in the situation didn't call the police. This leads me to believe that most people who would claim that they would call the police would be lying, and I might be included. As much as I'd like to think I would do the right thing, I would have to say it would depend on the circumstances. "I was tired" sounds like a poor excuse. However, I will admit that if I was woken up by the noises in the middle of the night, I might be too tired to process what was happening. Sometimes when I wake up I discover I have turned my alarm clock off with no memory of doing so. I might wake up, hear what was happening outside, but be too delirious to really do anything and simply fall asleep. Another excuse was someone who thought it was lovers fighting. I definitely would not call the police if I was not aware of the gravity of the situation. Finally, if I saw the killer run away, and saw the victim returning home, seemingly unhurt, I might think things were fine. Basically, I think I would call the police if I was fully aware of what was happening. I would have to be conscious and awake, and I would have to realize that it was literally murder that was occurring.
Would I get involved in the situation? That would be very unlikely. After all, even if I thought getting involved would be helpful, I would be the last person in my home that would make sense to do something. If I was an adult living alone, I still doubt I would try and fight the murderer. I might come outside and say something; if the murderer knew I called the police, he might run away without me putting myself in any danger. The only time I think I might possibly endanger myself would be if it was someone close to me being attacked. Even then, I might be too scared in the actual circumstances.