RAWALPINDI: Pakistan Tehreek-e-Insaf’s incarcerated founder Imran Khan has refused a polygraph test (lie detector test) requested by the Lahore police investigation for the fourth time, delaying progress in the probe into the May 9 riots case. A police investigation team, headed by DSP Asif Javed from Lahore, arrived at Adiala Jail on Monday to conduct a polygraph test, photogrammetric test, …