HRW: IS execute three times more people in Tikrit than previously thought

Still from an IS video. The man between the lines is Ali, one of HRW´s witnesses. 
 
Human Rights Watch has found new evidence that the Islamic State (IS) in Tikrit after it seized the city in June 2014, in fact carried out three times more executions than earlier was estimated. Information from a survivor and analysis of videos and satellite imagery has confirmed the existence of three more mass execution sites, bringing the total to five, and the number of dead to between 560 and 770 men, all or most of them apparently captured Iraqi army soldiers.
Islamic State fighters took control of Tikrit on June 11. The next day it claimed to have executed 1,700 “Shi’a members of the army,” posting videos of hundreds of captured men in civilian clothes, who it claimed had surrendered at the nearby Iraqi Speicher military base.
Photos later posted on social media showed IS fighters loading captives in civilian clothes onto trucks and forcing them to lie in three shallow trenches with their hands bound. Some images showed masked gunmen firing weapons at these men.
Based on an analysis of satellite imagery and photographs available at the time, Human Rights Watch concluded on June 27 that two of the trenches were in a field about 100 meters north of the Water Palace in Tikrit. The location of the third trench was not identified.After analyzing a recently released Islamic State video of the execution of detainees and satellite imagery, Human Rights Watch has identified three new execution sites from that period, with an additional death toll of between 285 and 440. The locations of two of the sites have been precisely identified based on the imagery and witness evidence, while the location of the third site remains approximate based on the account of a survivor.