Marlin James Mack Jr., 25, shot and injured three police officers before he was killed in series of gunfights with authorities in east Kansas City last month. The convicted felon was initially a suspect in the killing of a UMKC graduate student back in June. He was reportedly identified on video surveillance prior to gunning down Sharath Koppu during a robbery at J’s Fish and Chicken Market.

Prior to be being tracked down by officials; Mack was able to purchase a high-powered firearm at a gun store one day before authorities confronted him. Mack already had a number of felony convictions, which should have automatically disqualified him from purchasing the AK-47 pistol he used in the shootouts. Authorities, including undercover detectives and tactical response personnel, confronted Mack at a motel on July 15. The suspect refused to surrender and instead opened fire at the arresting officers. Two officers were wounded during the initial gunfight. Mack was able to escape the arrest, but officers chased after him resulting in multiple shootouts. Mack shot and wounded another officer prior to being shot and killed near Topping Avenue.

According to investigators who were looking into why Mack was able to purchase a firearm, the suspect apparently used falsified information to pass the firearm background check. FBI Spokesperson Stephen Fischer revealed that Mack used “false biographical information” when he purchased the firearm. The information apparently did not match any record on the FBI National Instant Criminal Background Check System (NICS), which in turn allowed the purchase to proceed.

The store that Mack visited to purchase the firearm, The Armory KC, also revealed that Mack deliberately falsified some data during his application. According to the store, Mack used a different middle name and place of birth. However, Mack did use his real name and birth date on the application, which had matched with his Missouri driver’s license. According to a report from Fox, FBI Investigators should have pulled Mack’s record despite it having a different middle name. At the very least, investigators should have triggered a three-day hold until they can get more information.