Mumbai, Nov 26: How he came, how he operated and how he left. This continues to be a big mystery. David Coleman Headley, a US agent turned rogue is centric to the Mumbai 26/11 attack plot. He was the man who came several times to India to conduct a reconnaissance of the targets that the Lashkar-e-Tayiba terrorists were supposed to hit. Not once was this man on the radar of the Indian Intelligence agencies. He came to Mumbai befriended high profile personalities, went about his job without being suspected or detected even once.