Augmented Reality (AR) in human rights museums and memorialization efforts can empower these initiatives to create stronger connections between audiences and victims; however, there is little research on the risks of depicting sensitive narratives through immersive technologies. We examined the opportunities and challenges of applying AR to memorialization by designing and deploying an AR application with a human rights museum in Colombia. We report lessons from our collaboration about navigating the risk of re-victimizing testimonial authors while creating engaging AR interactions. Furthermore, we report on a user study where participants interacted with our museum exhibition. Based on observations of our co-design process and the user study results, we discuss implications for immersive application design with strategies for selecting immersive content, balancing audience engagement, and identifying technology gaps. Finally, we reflect on the implications for collaborations between HCI researchers, human rights professionals, and organizations to inform designs involving sensitive narratives.