New Delhi: Using his father as the main witness, NIA on Friday chargesheeted Islamic State operative Mohammad Naser, who designed flags and logos for the 'caliphate' and had managed to reach Sudan en route to Syria before he was caught and deported last December. His father Ameer Mohammed Packer had fled to India from Dubai on finding that his son was going to fight in Syria.Ameer's statement was recorded under section 164 CrPc, making him one of the most important witnesses against his son.The chargesheet filed before Special NIA Judge Amar Nath said while in Sudan, Naser had emailed his father an emotional message informing that he was happy there. "Take care of mom and Sumaiya and I am very safe here... Life here is wonderful. I want you all to come to Dawlah..."The mail, texts and WhatsApp communication between father and son was listed as clinching evidence by NIA. "Accused had confirmed to his father that he had joined IS and it was not possible for him to return to the mainstream," the chargesheet said. The court fixed June 9 for considering the chargesheet.The chargesheet said Naser, 23, had gone to Dubai in 2014 to look for a job after completing his BE from a Chennai college. He worked for some time as a web developer and graphic designer on a monthly salary of 2500 dirhams. He got redicalised after watching IS propaganda videos. He then stole his passport from his employers and left for Sudan without intimating them. Through an online group, he was in touch with Jaipur-based IndianOil manager Mohammad Sirajuddin, arrested last year as he was preparing to leave for Syria with his family. NIA will file a chargesheet against Sirajuddin on Saturday.