Dieter Riechmann, who had contacted police immediately after the murder, was arrested a few days later and jailed on a minor federal gun charge which was dismissed two months later. He was released from custody in December 1987, only to be immediately re-arrested by the Miami police and charged with the murder. At trial, the prosecution argued that Riechmann lived off Kischnick's earnings as a prostitute and killed her for insurance money when she became too ill to work.

    While Riechmann was being held in detention on the gun charge, the couple's apartment in south-west Germany was searched by local police officers. Further searches were carried out in the following months in the presence of the trial prosecutor from Florida, who also conducted numerous interviews among colleagues and acquaintances of the couple. In contrast, the defence attorney billed the courts for less than 20 hours of time spent on pre-trial investigations. Riechmann was convicted of first degree murder with the aggravating circumstances of pecuniary gain and premeditation. He was sentenced to death on 4 November 1988.

    Riechmann has asserted his innocence from the outset, maintaining that Kischnick was shot at close range by a stranger outside the car. He alleges that after dining out, he and Kischnick had lost their bearings in one of Miami's poorer neighbourhoods. When Riechmann pulled over to the kerb, Kischnick rolled down the window to ask a man for directions. According to Riechmann, the man shot his companion in one of the first in a series of random tourist killings carried out in Miami over the following years.
    Police records indicate that Riechmann was not informed upon detention of his right to notify the German Consulate in Miami for assistance, nor was the consulate automatically notified of his arrest as required under Florida law. See footnote 21 ²¹ However, since the victim was also a German national, her death had been reported to the German consular authorities in Miami.

    Evidence in support of Riechmann's version of events was presented at a hearing in May 1996, including findings from experts on firearms and blood spatter patterns and testimony from two eyewitnesses to the shooting. Based on its findings of ineffective assistance of counsel, the state's misconduct in withholding exculpatory evidence and errors in the penalty phase of his trial, the court upheld Riechmann's conviction but ordered that he be re-sentenced. The order for a new sentencing hearing was upheld by the Florida Supreme Court on 24 February 2000. In a recent development, another person is alleged to have confessed to shooting Kersten Kischnick.