Robert was a DHARMA Initiative crew, who was a new recruit in 1973. He may have been killed along with other members of the DHARMA Initiative in the Purge, or he may have been evacuated off the island sometime between 1977 and The Purge.
On the Island
After arrived on the island, Robert was welcomed by Casey, June and Mike, then he went to the Processing Center along with the other new recruits. Inside the center, Robert was standing in front of the television, and watching the Barracks video next to Earl. ("The Man Behind the Curtain")
When the new recruits of 1977 arrived on the island, Robert was seen walking to the Processing Center. Later, he was seen sitting inside the Center, and helped the new recruits. ("Namaste")