Perfect Mysteries:

Sure, he looks innocent, but is there more to Jonathan than meets the eye?  You are first introduced to him at the end of the first Area 51 mission.  You last see him at the end of the last Area 51 mission, where he offers to ride the hover bike out, while you and Elvis take the spaceship.  And that's all you see of him.  You are lead to believe that he didn't make it out.  Or are you?  When he is running to open the doors in Area 51: Escape, if you get in front of him, Joanna will tell him to get in the saucer with Elvis!  Then you take the hover bike out.  Then, in the Carrington Institute mission, Jonathan will be in there, as a guard!  He has his magnum, and he can shoot guys, and die.  But don't you think that he should do a little more if he is included in the "Key Personnel" section of the instruction booklet?
Here us a picture of Jonathan as a guard in the Carrington Institute: Defense mission. 
Unfortunatly, he is completely mortal, and he can be killed.  I just had to find out.