THE Sandton woman who drugged her two sons before setting their home alight has walked free after a court found she was psychotic when the crime was committed and could not appreciate the wrongfulness of her act. Dr Manuela Costa was found “not guilty due to mental illness” after she set alight her Morningside Manor home, killing her sons Michael, 11, and Andre, 9. Two other sons, Filipe and Daniel Gil, survived the blaze that destroyed the R1m home in November 1998. Costa, who suffered burns and smoke inhalation, had recently been diagnosed with cancer, had a R800 000 judgment against her and was to be evicted from her home. State and private psychiatrists agreed her mental state meant she could not be held responsible.