I think Tulsi badly needs a revised check mark scheme to solve problems, because the current one has failed her too many times.
1. Keep eyes and ears open on mistakes and crimes made and lies being told. Remember this is SN, many evils reside her and a disaster is waiting to happen.
2. Find the origin of mistake and who the victims are. Take notepad and plan out who, what and how you are going to investigate the crime.
3. DO NOT UNDER ANY CIRCUMSTANCE believe anybody. Complete investigation on your own. Everyone is a suspect (except Ba), interview everybody in your family because most probably one of them is the culprit, never forget SN is resident evil. Take constant notes of what everyone is saying so you can remember and cross check their stories later. Always assume that they will all lie first. So multiple interviews of the same person might be required.
4. You might find evidence along the way implicating somebody. Assume that they are planted, then find out if the evidence is genuine and if it is substantial. Keep all the evidence in a locked room that only you have access to in case of tampering. Make full use of available criminal forensics, remeber finger printing and DNA testing.
5. At night sneak into every possible suspect room to check if there is any implicating evidence against them, or if they are hiding anything, or they are not mumbling anything in their sleep in guilt. Remember at all times you have the full authority to eavesdrop in convesations and listen in on phone conversations. Remember at no point in time let the SN members be aware that you are conducting an investigation, all in secrecy.
6. Zero in on the culprit. Make sure once again to go to the scene of the crime and know exactly how the crime was committed. Talk with the victims again and interivew them thoroughly.
7. Once you suspect somebody. Repeat steps 3 to 6 one more time to make sure you reach the same conclusion.
8. Then go to the police and calmly give them all your collected forensic work and repeat to them how you reached this conlusion.
9. Then the police will arrest the culprit(s) and remind the police to never take your name as the principle investigator because you are SN family members favorite punching bag.
10. After all this hard work. Kick back and relax for a while watch a comedy laugh a little. Because in a while another crime will be committed you need to get the game face on and might have to cry a little.