In a major breakthrough, one of the seven persons who allegedly carried out the Taliban-style attack on a college lecturer in Moovattupuzaha, Kerala, has been arrested by the special investigation team probing the case. Acting on information, the personnel of the special investigation team took into custody Shamsudeen alias Shamsu of Arackapady in Ernakulam district from Ukkadam on the outskirts of Coimbatore in Tamil Nadu on Thursday night.