On Oct. 23, 2021, Kiefer made plans to go shopping with a friend, who drove Kiefer to Parker’s home so she could pick up her credit card. Kiefer went inside the home while the friend and her 1-year-old twins remained in the car. Kiefer walked out of the house and the friend saw Kiefer and Parker "engaging in a verbal argument on the front porch."
Kiefer walked back to the car, but as she opened the door, Parker "pulled Kiefer away from the car and began stabbing her with a knife."
The friend saw Kiefer on the ground covered in blood and tried to help her, but Parker reportedly started running after her. As the friend got back into her car, Parker got into his vehicle and crashed into her car before driving off. The friend called 911 and described both Parker and his red Acura sedan.
Police arrived at the scene and Kiefer was taken to Stony Brook University Hospital, where she went into cardiac arrest and died "within minutes" of arriving. According to the District Attorney’s Office, Kiefer sustained 54 stab wounds to the head, torso, face, and neck, as well as defensive wounds on her hands.
Suffolk County Police learned Oct. 24, 2021, that Parker planned to take a bus from New York City to North Carolina. Detectives eventually found him on a bus traveling to that destination and detained him. He reportedly had a bandage on his hand due to a "massive laceration" inside his palm.
On Oct. 25, investigators located Parker’s Acura at a farm "with the interior of the vehicle covered in what appeared to be blood."
Inside the car, detectives uncovered a "tremendous amount of physical evidence," which included the folding knife he used in the fatal stabbing. Blood on the knife came back with a mix of DNA from both Kiefer and Parker. A dashboard camera reportedly recorded the attack as well.