A court in Yemen sentenced to death Abdel Aziz Yehia Hamoud al-Abdi, convicted of murdering Jewish teacher Moshe Yaish Nahari in December 2008.
Sunday's ruling overturned a previous sentence in March, that deemed Adbi as mentally incompetent and merely ordered him to pay a fine for the fatal shooting.
In March, the court said the defendant, a retired Yemeni Air Force pilot - was "mentally unstable." It ordered him to pay a fine of 50.5 million riyals, or about $250,000.
Following Sunday's ruling, al-Abdi's attorneys said they would file an appeal to the country's Supreme Court.