Born in 1979 in Kirkuk, Iraq, Louay Omar Mohammed al-Taei pursued medical studies at Mosul University, graduating in 2003. He began his medical career at al-Jumhuriya Hospital in Kirkuk, where he initially provided care to patients, including insurgents. In August 2005, he was recruited by the insurgent group Ansar al-Sunna, marking a turning point in his life.

Between October 2005 and March 2006, Dr. al-Taei exploited his position at al-Jumhuriya Hospital to murder 43 individuals, primarily wounded Iraqi police officers, soldiers, and officials. His methods included administering lethal drug cocktails and tampering with medical equipment, such as turning off oxygen supplies. Motivated by his opposition to the U.S. presence in Iraq and support for insurgent activities, he believed he could evade detection due to the lack of proper autopsy facilities. His actions were uncovered following the arrest of Malla Yassin, a senior member of Ansar al-Sunna, leading to al-Taei's apprehension in March 2006.