Samaha and Syrian Maj. Gen. Ali Mamlouk in August were charged in Lebanon with plotting to kill key political figures and launch terrorist attacks in the country. Samaha is in Lebanese custody.
The U.S. Treasury Department sanctioned Samaha in December, saying he was "contributing to the breakdown of the rule of law in Lebanon."
A military judge requested the death penalty for Samaha, Mamlouk and a Syrian security official identified by The Daily Star newspaper in Lebanon only as Col. Adnan for their role in the plots.
The Lebanese newspaper states the men were charged with plotting to assassinate Syrian opposition figures from Damascus.
Internal political skirmishes and kidnappings in Lebanon have sparked concern the civil war in Syria could spill across the borders.
Samaha was accused of carrying bombs in his car as he traveled from Syria to Lebanon. Samaha was quoted as telling a Lebanese police informant that it's OK to kill religious leaders gathered for a dinner breaking the daily fast for Ramadan.