The court in the coastal city of Mombasa ruled yesterday that there was insufficient evidence to convict the man, identified in court documents as Michael Bibcke Robel, 43, from the city of Hamburg, of murdering Esther Elsi Igoki Munyi in December 2009.
The court heard how the accused was found sleeping next to his dead, decomposing wife at their home near Mombasa after police were alerted by the smell. The accused had also stabbed himself in the chest in an apparent failed suicide attempt.
She also ruled that there were no eyewitnesses to the events, and that an autopsy failed to establish the precise cause of death beyond that of asphyxia, partly because the body was decomposing when it was discovered.
Judge Odero said the fact the man had remained with his wife's decomposing body for several days was further evidence of his mental instability, supporting a finding by doctors that he was suffering from mental illness.
Court officials said the man was handed over to a German embassy representative after the trial. The German embassy in Nairobi could not immediately be reached for comment.