On April 17, 1983, Felix Pappalardi was shot once in the neck in their fifth-floor East Side Manhattan apartment. He was pronounced dead at the scene and Collins Pappalardi was charged with second degree murder. Collins Pappalardi claimed that the killing was an accident. She was acquitted of second degree murder and manslaughter, but found guilty of criminally negligent homicide. On April 30, 1985, she was released on parole.
On December 6, 2013, Collins was found dead by her landlord in the Mexican village of Ajijic, Jalisco, a resort town with many American expatriate residents. She had been undergoing cancer treatments there. She was cremated.