** (Disclaimer: This video content is intended for educational and informational purposes only) ** Los Angeles police released graphic bodycam footage showing a police shooting in Van Nuys that left a knife-wielding suspect and an innocent bystander dead last month. The LAPD showed the graphic video during a press conference Tuesday morning. The footage was recorded on body-worn cameras from the officers involved in the incident. The incident occurred on June 16, when officers with LAPD's Van Nuys Division received a radio call about a man who had stabbed his ex-girlfriend with a knife, LAPD Chief Michel Moore said. Responding officers confronted Guillermo Perez outside of a church on Tyrone Avenue. Perez was holding a metal folding chair and a large knife, Moore said. Officers told him to drop the knife, but he ignored their commands. That's when police fired bean bag rounds at Perez, Moore said. "He moved away from officers and grabbed an innocent bystander who was standing nearby. Perez began to cut the innocent bystander's throat with a knife. That's when three officers shot at Perez to stop his actions and prevent him from killing the hostage," the chief said. Officers fired 18 rounds, and Perez was shot and killed. The innocent bystander, 49-year-old Elizabeth Tollison, was struck twice by police gunfire, and she later died at a hospital, Moore said. Moore said there's much more work to be done in the investigation before he is able to provide recommendations on the actions of the officers involved. The investigation will look into whether proper procedures were followed. The chief said it's been 13 years since an officer's gunfire killed an innocent bystander or hostage. In the last six weeks, it's happened twice -- the most recent being the incident at a Trader Joe's market in Silver Lake, where a store manager was killed by police gunfire in a shootout between LAPD and a standoff suspect. "The life of the hostage is paramount and protecting that individual from the threat of the assailant, and in doing that, the balancing act that the officer has - is how to protect them by stopping the suspect's actions," Moore said. "This was a tense situation that unfolded very quickly. It's every officer's worst nightmare." Perez had a very violent past. He was released from prison and also convicted of robbery. He was a documented gang member who was arrested for assault with a deadly weapon and domestic violence. Donate to PoliceActivity: https://www.patreon.com/PoliceActivity Like us on Facebook: https://www.facebook.com/PoliceActivity Follow us on Twitter: https://twitter.com/Police_Activity