When defending the defendant, you may consider the following aspects to explain his motives and the legality of his actions: 1. **Motive explanation**: Emphasize that the defendant's real motivation is to study and evaluate gun control policies. He did not break the law with malice or intent, but wanted to understand the impact of the policy through personal experience. 2. **Evidence support**: If possible, provide evidence of the defendant's participation in relevant research or community discussions, such as meeting minutes, questionnaires, or other relevant activities, to prove his concern and investment in this issue. 3. **Expert testimony**: Consider inviting experts in gun control policies to testify, explaining the importance of personal experience to policy research and the rationality of the defendant's behavior in a specific context. 4. **Legal framework**: Analyze local gun laws, explore the specific circumstances of the defendant's possession of weapons, and whether there are reasonable legal interpretations or applicable exceptions. 5. **Harmlessness**: Emphasize that the defendant's behavior did not cause harm to society, and the time and manner in which he held weapons did not pose a threat to others, further proving that his motives were good. 6. **Seeking reconciliation**: If the law permits, explore whether the case can be resolved through reconciliation or restorative justice measures instead of severe criminal penalties, so that the defendant can continue his research. In this way, you can build a defense framework around the defendant's good intentions and seek a lighter sentence or a favorable verdict.