Chief Petty Officer Mendez
From Halopedia, the Halo wiki
Summary
Chief Petty Officer Mendez was the Spartan's training leader during their first years on Reach. He trained them as hard as any Marine when they were only at the ages of 6-7 years old. After their training was completed, he was reassigned to go train the next generation of Spartans, though he has not been heard of for some time. It may be assumed he was killed, along with any young Spartans he may have been training, when Reach fell during the invasion. He is currently listed as MIA.
