FBI opens an investigation into the death of Breonna Taylor

The FBI in Louisville, Kentucky, has opened an investigation into the police-involved shooting death of front-line worker Breonna Taylor.

Taylor and her boyfriend, Kenneth Walker, were sleeping inside their Springfield Drive apartment on March 13 when officers with the Louisville Metro Police Department attempted to execute a "no-knock" search warrant.

Three plainclothes officers opened Taylor's front door and "blindly" opened fire into their apartment, according to a wrongful death lawsuit filed in April by Taylor's mother, Tamika Palmer.

Taylor, a licensed EMT, was shot at least eight times and died.

"The FBI will collect all available facts and and evidence and will ensure that the investigation is conducted in a fair, thorough and impartial manner. As this is an ongoing investigation, we are not able to comment further at this time," said Special Agent in Charge Robert Brown in a statement on Thursday.

Taylor was accused of accepting USPS packages for an ex-boyfriend who police were investigating as an alleged drug trafficker and used her address, according to the warrant.

The police said they knocked several times before using a ram to open the door and were allegedly met with gunfire. Walker said he called 911 before firing one shot from his licensed firearm.

Walker, 27, was charged with shooting Sgt. Jonathan Mattingly in the leg.

Jefferson County Attorney Tom Wine said on Friday that while Mattingly's injury was not a result of "friendly fire" he agreed to dismiss Walker's charges pending indictment.

"I believe additional investigation is necessary," said Wine at a press conference. "I believe the independent investigation by the attorney general's office of Kentucky, FBI and U.S. attorneys office must be completed before we go forward with any prosecution of Kenneth Walker and if after those reviews we believe there is sufficient evidence to present to the grand jury we will do so."

Mattingly and Officers Brett Hankinson and Myles Cosgrove were placed on administrative reassignment pending an investigation and are named as defendants in the lawsuit. An investigation is also being conducted by the Louisville Metro Police Department's Public Integrity Unit.

"Kenneth Walker and Breonna Taylor did everything right the night police ambushed their home, killing Breonna," said attorney Ben Crump on Friday. "While dismissing the charges is the right thing to do, it comes more than two months after Breonna was killed and Kenneth was arrested...Until everyone involved is held accountable and the full truth of what happened that night is revealed, justice for Kenneth and Breonna is incomplete."

Louisville Police Department Chief Steve Conrad said at a press conference after the shooting the officers who worked with their criminal interdiction unit did not wear body cameras.

Conrad announced his retirement on Facebook Thursday after a "40-year career in law enforcement" but will continue to work until June 30 on administrative duties. Col. Rob Schroader will come on as the interim chief on July 1.

"You all are weathering a lot right now and I know how challenging this is. Approach this as we approach all our struggles — as a team. Look out for each other," wrote Conrad on the Facebook post. "Show compassion to the community, even when it might not be shown to you."

Palmer's attorneys Crump, Sam Aguiar and Lonita Baker saw Conrad's announcement as a "resignation."

"[It] was a significant step forward in getting justice for Breonna Taylor, her family, and the city of Louisville. But this is just the beginning of that journey," the attorneys said in a joint statement. "We look forward to further investigation, including by the FBI, into the chain of events that led to Breonna’s tragic and preventable death."

ABC News' Sabina Ghebremedhin contributed to this report.