Ömer Halisdemir, who changed the course of the coup attempt and became a symbol of the resistance, obeyed the order from Special Forces Commander Zekai Aksakallı without question despite knowing it would lead to certain death. Halisdemir played a heroic role preventing the success of the coup attempt by killing putschist Brig. Gen. Semih Terzi. Putschist soldiers shot Halisdemir multiple times, killing him on instantly.
Halisdemir is one of the seven sons of Hasan Hüseyin Halisdemir, who lives in the village of Çukurkuyu in Niğde. Halisdemir spent his childhood in the village and worked as a shepherd after school. He married his wife Hatice and had two children, Elifnur and Doğan Ertuğrul. Halisdemir joined Turkish Armed Forces (TAF) as an infantry noncommissioned officer in 1999. Halisdemir, who carried out several tasks for the TAF inside and outside of the country, became an unforgettable hero for what he did on the night of July 15.
Last order: Kill him before he gets in the quarters!
Special Forces Commander Zekai Aksakallı managed to escape the ambush after his official car was trapped by three vehicles on the way to Külliye on the night of the coup attempt. Aksakallı, who saw that there was a coup attempt happening and that putschist soldiers wanted to seize the Special Forces Command, called the man he trusted the most and tried to reach the commissioned officers on duty. He told his trusted troops to come in front of the command building with their weapons.
When Aksakallı called the quarters, he learned that Terzi gave the order: “I’m coming there. Secure the barracks. Don’t let any of the commanders in. Shoot them if necessary.” Aksakallı called Halisdemir, and described the moments as follows: “I’m giving you a historical task for our nation. Brig. Gen.l Terzi is a traitor. Kill him before he gets in the quarters. There’s a martyr’s death at the end of this. We have been together in this for 20 years. Renounce your rights for me in this.”
Halisdemir responded to Aksakallı after this order in a dignified voice, and said: "Yes, sir! I renounce my rights. You do it too.”
They shot Halisdemir from behind
Terzi, who had been working at Silopi, came to the Special Forces Command in a helicopter around 2:16 a.m. Halisdemir grabbed his gun on Aksakallı’s order and hid in the woods by the building’s entrance. He mingled with the putschist soldiers and shot Terzi three times. While Terzi was falling, Halisdemir ran toward the nearby woods. The soldiers who were with Terzi started shooting Halisdemir from behind. Halisdemir was shot 15 times. It was understood that it was Maj. Fatih Şahin who shot Halisdemir first. It was found that Şahin fired 12 shots. 
They shot him again after seeing he was not dead
Putschist soldiers moved Terzi’s body to the military headquarters. Halisdemir, who was severly injured, was brought to the front of the quarters from the woods. An ambulance on duty at the Special Forces Command arrived at this moment, but did not help Halisdemir on orders from the soldiers there who then started shooting Halisdemir cruelly after they checked his pulse and found that he was not dead. It was found that it was Lt. Mihrali Atmaca was responsible. The soldiers sent the ambulance off. It was found that the soldiers took Terzi to Gülhane Military Medical Academy (GMMA) as soon as possible, but left Halisdemir’s body on the ground in front of the quarters. Terzi died in the helicopter before he could arrive at the hospital. 
The name of the hero shall never be forgotten
Halisdemir was buried in his hometown of the Çukurkuyu in the Bor district of Niğde after dying a martyr’s death at 42 years old. Halisdemir’s father, who stood with pride at the funeral, said these unforgettable words: “I raised him for our country. Our country wanted him and I gave him to our country!”
The name of Martyr Master Chief Petty Officer Ömer Halisdemir was given to Niğde University, a high school in Etimesgut in Ankara, a middle school in the district Yunusemre in Manisa, an elementary school in Kahramanmaraş, an Anatolian imam hatip high school in İzmir, an imam hatip high school in Yenimahalle in Ankara and an Anatolian Yenimahalle in Çekmeköy in Istanbul.
Halisdemir’s grave has been visited by 100,000 people.
