British investigators believe the March 4 attack on the former spy, Sergei V. Skripal, and his daughter, Yulia, was most probably carried out by current or former agents of the service, known as the G.R.U., who were sent to his home in southern England, according to one British official, one American official and one former American official familiar with the inquiry, speaking on the condition of anonymity to discuss intelligence, NYT reports.
British officials are now closing in on identifying the individuals they believe carried out the operation, said the former American official. At the same time, investigators have not ruled out the possibility that another Russian intelligence agency, or a privatized spinoff, could be responsible.
