Here are the key players in the trial of the former Louisville police officer connected to Breonna Taylor's killing

Myles Cosgrove, Brett Hankison and John Mattingly were the Louisville police officers who fired their weapons during the 2020 raid in Breonna Taylor's apartment in Kentucky.

(CNN)Nearly two years after a botched police raid led to Breonna Taylor's death, the only officer facing criminal charges for his actions on that day is standing trial in Kentucky.

Brett Hankison, a former Louisville Metro Police Department officer, is facing three counts of felony wanton endangerment in the March 2020 shooting in Louisville, Kentucky. Hankison pleaded not guilty to the charges.
While Hankison was among several officers who took part in the raid on Taylor's apartment, the three felony counts are for endangering the people in a neighboring apartment, according to the state attorney general. He is not charged in Taylor's death.
      The counts against Hankison have so far been the only criminal charges issued by authorities in relation to the raid, even after Taylor's killing sparked protests across the country and renewed conversations about police brutality against Black women. Activists and Taylor's family continue pushing for police officers to be charged in Taylor's killing.
        Here's a look at the people tied to the case:

          Breonna Taylor

          A memorial to Breonna Taylor in Louisville, Kentucky.
          Taylor, 26, had been working as a certified emergency medical technician at the time of her death but her goal was to become a nurse. Her family nicknamed her "Breewayy" -- because whatever she wanted, she found a way to make it happen.
          On March 13, 2020, Taylor and her boyfriend were in bed in her apartment in Louisville's South End when police attempted to serve a search warrant on her apartment shortly after 12:30 a.m. in a series of raids related to Taylor's ex-boyfriend. They eventually used a battering ram to open the door. Taylor's boyfriend, armed with a handgun and fearing an intruder, fired one shot, and police officers returned fire, killing Taylor, who was shot eight times.
          The city of Louisville agreed to pay $12 million and institute sweeping police reforms in a historic settlement of the wrongful death lawsuit filed by Taylor's family. The lawsuit against three Louisville police officers involved in the raid, accused them of battery, wrongful death, excessive force, negligence and gross negligence.
          People across the country have repeated Taylor's name loudly and often; in the streets and online, as they demand justice in her death. Like the police killing of George Floyd in Minneapolis, Taylor's death fueled ongoing nationwide conversations over racial injustice and police brutality.

          Brett Hankison

          Brett Hankison, left, exits a Kentucky courtroom after the first day of jury selection in his trial earlier this month.
          Hankison was a detective with the Louisville Metro Police Department's criminal interdiction when Louisville officers burst into Taylor's apartment after midnight with a no-knock warrant.
          He was standing outside Taylor's apartment and blindly fired 10 rounds through a door and window. The bullets entered an adjacent apartment where a pregnant woman, a man and a child were home, according to the state attorney general.
          More than three months after Taylor's death, the then-police chief ordered Hankison's termination saying he violated standard operating procedure when his "actions displayed an extreme indifference to the value of human life." He has appealed his termination and a decision remains pending.
          "I find your conduct a shock to the conscience," former LMPD Chief Robert Schroeder wrote in a letter to Hankison. "Your actions have brought discredit upon yourself and the Department ... and demands your termination."
          A grand jury indicted Hankison in September 2020 after months of anticipation that a Kentucky grand jury would deliver justice in Taylor's killing.
          In audio from the closed-door grand jury proceedings, Hankison told investigators that he fired his weapon fearing for his own life and those of his colleagues because he felt the officers were "sitting ducks."
          Hankison said he wasn't supposed to be working that night as it was his scheduled day off. He wasn't an investigator on the case but he answered an "all-call" email for help to serve four scheduled warrants, he told investigators.

          Taylor's boyfriend

          Breonna Taylor and her boyfriend Kenneth Walker
          Kenneth Walker III, 28, was inside Taylor's apartment when police arrived. He was arrested and accused of shooting a police officer officer during the raid. Last year, a Kentucky judge dismissed the charges "with prejudice," meaning Walker can't be charged with the same offenses related to the shooting, according to court documents.
          Walker told investigators he heard banging at the door and assumed it was Taylor's ex-boyfriend, Jamarcus Glover. Taylor, who had awoken, shouted, "Who is it?" but Walker said there was no response.
          He said he and Taylor scrambled to get dressed and that he grabbed his gun, which his attorney has said he legally owns. He said both he and Taylor were yelling, "Who is it?" but received no response.
          As they made their way toward the front door, Walker said, the door flew off its hinges.
          "So I just let off one shot," he said. "I still can't see who it is or anything."
          Police then returned fire, killing Taylor. There is no police body camera video of what transpired in the moments after officers broke through Taylor's door. Police said they identified themselves and didn't knock the door off its hinges but did use a battering ram to open the door.

          Taylor's ex-boyfriend

          Jamarcus Glover in a  Louisville Metro Police Department photo.
          Jamarcus Glover was the focus of the Louisville police narcotics investigation that led plainclothes officers to execute a warrant on Taylor's home. He had previously dated Taylor on-and-off for seven years, Walker told investigators.
          Police said Glover, who was suspected of supplying a local drug house, had recently used Taylor's residence as his "current home address," according to an affidavit for a search warrant. The detective who wrote the affidavit said he saw Glover walk into Taylor's apartment in mid-January and leave with a package before going to a "known drug house." Taylor's apartment was one of five locations police obtained search warrants for as part of the investigation.
          Glover was arrested elsewhere during a series of raids that day but was released on bail.
          Taylor's family and their attorney have maintained that she was not involved in her ex-boyfriend's alleged drug deals.
          Glover told the Louisville Courier Journal that police used misleading and wrong information to obtain the warrant, during which Taylor was fatally shot.
          "The police are trying to make it out to be my fault and turning the whole community out here making it look like I brought this to Breonna's door," Glover told the newspaper. "There was nothing never there or anything ever there, and at the end of the day, they went about it the wrong way and lied on that search warrant and shot that girl out there."

          Retired LMPD police Sgt. Jonathan Mattingly

          Jonathan Mattingly, a retired Louisville Metro Police Department sergeant, was one of the three officers who fired their weapons that night.
          Neither Mattingly or the other officers wore body cameras, the police department said, because they were plainclothes narcotics officers.