Presuposisi, berasal dari kata presuppose yang berarti to suppose beforehand, berhubungan dengan asumsi yang dimiliki penutur dalam bertutur dan memiliki karakteristik taken for granted. Presuposisi dapat ditemukan dalam percakapan dikarenakan adanya pemicu presuposisi, yang salah satunya adalah pertanyaan. Interogasi di pengadilan adalah situasi ditemukannya banyak pertanyaan. Presuposisi dapat ditemukan di sidang kasus pembunuhan Shannon Griffin dengan terdakwa Jennifer Mee yang berlangsung pada tahun 2013 silam. Tujuan penelitian ini adalah untuk menemukan trigger presuposisi, bentuk trigger pertanyaan, dan menemukan konteks kegagalan presuposisi dalam sidang kasus pembunuhan Shannon Griffin. Penelitian ini termasuk dalam penelitian deskriptif kualitatif. Data dikumpulkan dengan melakukan teknik catat percakapan dalam video persidangan kasus pembunuhan Shannon Griffin kemudian melakukan transkripsi secara manual. Kemudian, data diterjemahkan ke dalam bahasa Indonesia. Data dianalisis dengan mengklasifikasikan percakapan berdasarkan trigger presuposisi yang ditemukan, bentuk trigger pertanyaan serta konteks yang menggagalkan presuposisi. Terdapat 182 trigger yang ditemukan dari keseluruhan data dan termasuk dalam delapan kelompok trigger. Kelompok trigger tersebut adalah change of state verbs, factive verbs, iterative, question, counterfactual conditional, definite description, temporal clause dan cleft sentence. Trigger yang ditemukan sendiri didominasi oleh trigger pertanyaan (116 buah, 63%). Selanjutnya, trigger pertanyaan pun ditemukan dalam berbagai bentuk, seperti yes/no question, alternative question, WH-question, tag question dan counterfactual conditional. Bentuk trigger pertanyaan yang paling dominan adalah trigger pertanyaan dalam bentuk yes/no question (84%) dengan fungsi untuk meminta konfirmasi. Sementara itu, kegagalan presuposisi disebabkan oleh beberapa konteks, yaitu karena konteks perbedaan pengetahuan, kurangnya pengetahuan lawan tutur mengenai topik tertentu, dan adanya bukti yang melawan asumsi penutur.

Presuppositions, comes from the word presuppose which means to suppose beforehand, related to assumption which is had by speaker in speaking and has a characteristic as taken for granted. Presuppositions can be found in conversation due to the existence of presupposition triggers, one of them is questions. Investigation in the court is one of the situations where many questions can be found. Presupposition also can be found in Shannon Griffin murder trial with the defendant Jennifer Mee which occurred in 2013. The purpose of this research is to describe triggers of presuppositions, to describe the form of questions as presuppositions trigger, and to describe the contexts of presuppositions failure in Shannon Griffin Murder trial. This research belongs to qualitative descriptive method. Data were collected by conducting note-taking technique to note the conversation in the video of the murder trial of Shannon Griffin, then the transcription was done manually. Afterwards, data were translated to Indonesian. The data were analyzed by classifying the conversation based on presuppositions triggers which were found and by describing the form of questions as presuppositions' trigger, and by describing the context of presuppositions failure. There were found 182 triggers from all the data and they belong to eight triggers groups. The triggers belong to change of state verbs, factive verbs, iterative, question, counterfactual conditional, definite description, temporal clause and cleft sentence. The most dominant trigger found was questions (63%). Meanwhile, questions as presuppositions trigger were found in many forms, such as yes/no question, alternative question, WH-question, tag question, and counterfactual conditional. The most dominant form of questions as presuppositions trigger was yes/no question (84%). Moreover, presuppositions failure was caused by some contexts, they were the context were the speaker and hearer had different common knowledge, hearer lacks knowledge about a certain topic, and the context where evidence appeared to reject the speaker's assumption.

Kata Kunci : presuposisi, triggers, pragmatik, wacana pengadilan, linguistik forensik