Arop-Lokep, an Austronesian language of Papua New Guinea, has a contrast between a trilled /r/ and a geminate /rr/ in both intervocalic and word-initial positions. This paper presents the results of acoustic and perceptual experiments involving these segments. Specifically, we probe the statistical characteristics of the /r/ vs. /rr/ contrast across prosodic positions from the perspective of both the speaker and the listener. We measure trills in 24 different Arop-Lokep words, so the resulting data are quite robust and give an excellent idea of the variation inherent in the language. A novel finding is that both lengths of trill consist of more apical contacts word-initially than intervocalically. The scope of this work is unprecedented in that no previous instrumental study has examined both initial and medial geminate trills in the same language.