The Lieutenant was an NPC, an officer in Senator Padme Amidala's party as it was flying to Coruscant to vote on bills for creating a Grand Army of the Republic and for building a new moon for Naboo to replace the one destroyed by the Trade Federation.
Silence of the Clones Edit
As their ship was beginning its final approach to Coruscant, the Lieutenant infromed Senator Amidala of that fact.
A New Generation Edit
If the Lieutenant was still alive 22 years later and was living on Naboo at the time, he was most likely killed along with everyone else on Naboo when Darth Vader ordered the planet's destruction from the Peace Moon's laser.