Parents can feel panicky when this starts to happen, and the danger is that a knee-jerk reaction of pulling in the reins too tightly will occur, and then this will exacerbate the whole syndrome. Anyone interfering with it is the enemy. This transition, from dependence to autonomy, can seem to happen overnight, and is experienced as a terrific shock by many loving parents, who are seldom ready to change their approach as quickly as the child needs them to. The lying has the advantage of establishing distance between himself and you. You try to get him back by forcing obedience, but this won't work.
Peers are second only to autonomy in the adolescent's scheme of things.
I have known kids to come home from school and immediately telephone the friends they have just been talking with five minutes before. I suggest you sit down with your son and discuss the incident you relate in your letter. Tell him you understand that he is at the age where he needs to feel more involved in running his own life, and that you cannot control him. This is essential. He may or may not take you up on it, in this case, and you cannot force him.