If you were Langdon and the police wanted to question you about Jacques' murder, what would you do?

If I were Langdon and the police were questioning me about the murder of Jacques I would tell the truth. Although I would realize that it was suspicious that I planned a meeting with Jacques that night, I would know that I had nothing to hide. By cooperating, I might be able to assist the police in their investigation and, thus, clear my name faster.