Kenneth Walker, the boyfriend of Breonna Taylor who was killed by police one year ago Saturday, filed a lawsuit against the Louisville city government and police claiming that false statements were used to obtain a search warrant that ultimately led to Taylor’s homicide, the Washington Post reports.

In a 38-page-lawsuit, Walker alleges that Taylor’s death was preventable and that systemic problems within the city government and police department led to the series of events that resulted in the homicide.

Taylor, a 26-year-old EMT, was killed one year ago when police executed a warrant, originally a no-knock warrant, in the middle of the night.  Walker claims police didn’t announce themselves, and he responded to police breaking down by firing a weapon at them once, hitting an officer in the leg.  Officers returned fire, killing Taylor.

Numerous witnesses confirm Walker’s account that police didn’t announce themselves before breaking in the door, prompting Walker to fire.  The two officers who broke down the door were not charged with the homicide, but an officer who fired randomly from a patio was charged with wanton endangerment for bullets that entered a neighboring apartment.

Walker claims police used false information, claiming a postal inspector had linked a package to Taylor’s apartment, to get the warrant.  He also alleges that police did not properly oversee warrant applications.

Police originally charged Walker with firing on the officers, but later dropped the charges.  Last week, a judge ruled that Walker cannot be charged.