(KRON) -- A 19-year-old Sunnyvale man was struggling with mental health when he called 911 on himself. Emmanuel Perez Becerra was naked from the waist down as he talked to dispatchers and walked around his neighborhood on March 23, 2024, police body camera videos show. A Sunnyvale Department of Public Safety officer shot Becerra to death minutes after he arrived at Plaza Del Rey mobile home park, where the teenager lived. The teen was holding a large kitchen knife when the officer opened fire. This week, attorneys representing the teenager's parents filed a federal civil rights lawsuit against the officer and the city. Becerra's family said the teen's mental health began deteriorating ever since the COVID-19 pandemic. "Instead of receiving the help he was literally calling out for, Emmanuel was met with lethal violence. The results are heartbreaking and felt by his mother and father in ways that are immeasurable," said attorney Michael Slater of Oakland’s Pointer & Buelna, Lawyers for the People law firm. Leading up to the shooting, the dispatcher noticed that Becerra sounded "paranoid," according to a transcript of his 911 call. Becerra told the dispatcher that there was a naked man walking around his mobile home park with a knife, and he declined to answer follow-up questions. Emmanuel Perez Becerra When officers arrived, they found the teen walking through the empty streets of his neighborhood holding a kitchen knife. According to the lawsuit, Becerra never threatened anyone, or any of the officers. The first officer on scene, Sunnyvale Department of Public Safety Officer Kevin Lemos, jumped out of his patrol vehicle and ordered the teen to drop the knife at gunpoint, the lawsuit states. A second officer remained inside his vehicle. Lemos fatally shot Becerra in the chest after the teen started walking toward him, attorneys said. "The officer had a Taser. He had pepper spray. He had a baton," said civil rights attorney Adanté Pointer. "He never attempted to deescalate the situation, or to use non-lethal force, or to use any other method that might have avoided this needless loss of a young man’s life." Emmanuel Perez Becerra is seen moments before he was shot by police. (Image via City of Sunnyvale) Slater said, "Emmanuel had his whole life ahead of him. What happened to Emmanuel underscores why law enforcement should never respond to an individual in a mental health crisis by provoking and escalating the situation, and then immediately using deadly force as a first resort." Remorseless Fremont killer sings in front of murder victims’ families The lawsuit was filed in U.S. District Court, in San Jose, on behalf of the teen’s parents, Esmeralda Becerra Ochoa and Francisco Perez Mondragon. It accuses Officer Lemos of using excessive force, negligence, and wrongful death. Sunnyvale police released body camera videos of the incident last year. The teen's family previously told KRON4, "Emmanuel was truly a caring individual who was still healing from those pandemic impacts, and his opportunity to 'return to normalcy' with his loving and supportive family is now gone,” the family said