I think I witnessed a planned assassination
Oh wow. Do you know who planned it?
I suspect one person of planning it. However, I can't confirm my suspicions without evidence.
If you witnessed a murder, you should go to the police. Even if you think you know who is responsible, you should go looking for evidence or confront them, you should just tell the police what you know for your own safety.
Ha, I'm not actually talking about an assassination! I'm trying to speak about the bitch that stole my dessert and assassinated it!
Just want to be sure that you are serious here. If there is really someone in danger it is smart to let the authorities know. You could end up being a hero and save a life!