- "There have been people living there for over twenty years and they never complained about any hostile organism."
- ―Van Leuwen (from Aliens)
Van Leuwen was the chairman of the Interstellar Commerce Commission tribunal held in 2179 that reviewed the destruction of the USCSS Nostromo 57 years previously. Van Leuwen came to consider Ellen Ripley's judgement in the ship's destruction "questionable" and subsequently suspended her flight status.
Van Leuwen headed up the executive board that interviewed Ripley aboard Gateway Station in 2179 in order to ascertain what had caused her to destroy the Nostromo by self-destruct. After hearing Ripley's testimony for several hours, and despite acknowledging that the Nostromo had indeed set down on LV-426, Van Leuwen ultimately dismissed her claims that a hostile organism had been responsible for her actions, primarily citing the fact that no trace of the creature could be found anywhere on the shuttlecraft Narcissus. Despite the huge loss of investment the destruction of the Nostromo represented, he decided not to press criminal charges against Ripley. However, owing to her erratic behavior during the tribunal, he revoked her flight status and committed her to several months of psychiatric evaluations.
Following the tribunal, Van Leuwen casually explained to Ripley that another reason he had rejected her claims was that the colony of Hadley's Hope had been set up on LV-426 for more than twenty years and the people there had never discovered anything like the creature Ripley described. Ripley was horrified to learn that women and children were among the colonists living there.
- Several lines of Van Leuwen's dialogue later inspired the titles of trophies/achievements in the video game Aliens: Colonial Marines, including "Thank You, That Will Be All" from the expansion Stasis Interrupted.