Garth Grisan

Garth Grisan was the maintenance worker at Moon Base Alpha. He turned out to be working for the military and murdered Ronald Holtz to stop him from announcing the discovery of Zan Perfonic. However, his evil deed was discovered by various Lunarnauts and he was imprisoned before he could commit any more crimes.

(Picture is my imagination of him.)

Space Case
Garth Grisan's first appearance in the Moon Base Alpha series when he used a vacuum cleaner to suck up the moon dust that had floated off Ronald Holtz's corpse when him and Daphne Merritt carted the cadaver inside.

Garth was in the background for most of the rest of the book, but then his character was thrown into the spotlight again when he tried to kill Dashiell Gibson and Kira Howard with the base's Robot Arm. After that, Dash, Kira, Nina Stack, Maxwell Howard, Chang "Hi-Tech" Kowalski, Stephen Gibson, and Rose Harris all heard him threatening Dr. Holtz over voice recording in the Control Room.

Then, when Rose Harris figured out that Garth had actually murdered Ronald Holtz, Dash, Kira, Nina, Dr. Howard, and both Gibson Doctors dashed to the main airlock's staging area to confront Garth. Unfortunately, Garth was several steps ahead of them. He had his oxygen tank on and the airlock door almost open, prompting that he would release all of the oxygen out of the moon base if anyone tried to snatch him. But an unintentional distraction from Lars Sjoberg distracted Garth long enough that other Lunarnauts were able to wrestle him to the ground and arrest him before he could open the airlock.

Personality
Garth has a cold exterior and will stop at nothing to make his schemes come true.