Pro-coup Major Mehmet Karabekir, who shot and killed Mete Sertbaş, the mukhtar of Acıbadem neighborhood, and ordered the shooting of any civilian standing in the way, was captured dead on July 15 by Special Operations police in Istanbul's Üsküdar district.Pro-coup soldiers believed to be linked to the Gülenist Terror Organization (FETÖ) were attempting to take over Turkey's telecommunications center Türk Telekom in Istanbul's Acıbadem district when police and civilians, including Mukhtar Sertbaş tried to intervene and stop the traitor soldiers.Maj. Karabekir shot Mukhtar Sertbaş as he tried to intervene and stop the coup soldiers from entering Türk Telekom. Captain Karabekir then stopped other civilians, who were trying to take the injured muhktar to the hospital, from assisting him.Mukhtar Sertbaş died on the street after bleeding to death from the gunshot wound.Mobile phone messages between pro-coup officers appeared to reveal they ordered the shooting of people resisting the July 15 coup attempt.

As part of the investigation into the thwarted coup attempt, the Istanbul Prosecutor's Office compiled a series of WhatsApp messages between pro-coup officers, apparently sent on the evening of July 15.

Documents appeared to show that military officers in Istanbul were told - and ordered - to shoot at crowds resisting the coup.Maj. Mehmet Karabekir opened fire on the crowds and urged, "I am opening fire at the crowds and waiting. Use this in a restrained fashion. 10-15 people are dead. Do not lose initiative."In another exchange, Lt. Col. Ugur Coşkun says officers and soldiers have been overrun by a group of protestors at the Istanbul Governorship building.

In a reply, Maj. Karabekir says, "Crush them. Burn them. No compromise."The Turkish government has said the failed military overthrow was organized by followers of U.S.-based imam Fetullah Gülen, who is accused of a long-running campaign to overthrow the state through supporters within Turkish institutions, particularly the military, police and judiciary, forming what is commonly known as the parallel state.