Use the rewards

After each puzzle, you were given a reward. These rewards were letters. Could the letters help you to identify the culprit? Look at the names of the suspects in the gallery.
Rearrange the reward letters to spell out the name of the culprit. Only one of the suspects will have the correct letters in their name.
The rewards you were given were: i, f, e, t, n, j, and k. Look at the elf names on the suspect gallery. Only one contains these letters. JEF TINK