INDIANAPOLIS — Indy police are investigating after a person was shot and killed on the city's east side. A person of interest has been taken into custody. IMPD crews were called around 2:40 p.m. Tuesday to the 3600 block of N. Post Road on Indy's east side for a gunshot scene near 38th and Post. Upon arrival to the scene at Biomat USA Plasma Center, officers found one person suffering from gunshot wounds. IMPD confirmed around 3:20 p.m. that the person who was shot has been pronounced deceased. A person of interest has since been detained by IMPD and officials believe there is no threat to the public. Witnesses on the scene described hearing an argument inside the plasma donation office before hearing several gunshots. One witness said that people who were giving plasma ripped their IVs out of their arms to run outside, while others reportedly stayed inside. "My heart was beating so fast," one anonymous witness said. "I thought he was going to shoot everybody in there." When asked how many people were inside the building during the shooting, IMPD officials said they know of at least 10 witnesses.