According to this case, when does the duty to preserve arise?

Assignment 1:

Case: ACORN v. County of Nassau, 2009 U.S. Dist. LEXIS 19459 (E.D.N.Y. Mar. 9, 2009)

Using the case referenced above, please provide the following answers:

1. According to this case, when does the duty to preserve arise?
2. Define whatadverse inference instructionmeans and why such an instruction would be useful in a civil trial.
3. Why did plaintiffs in this case seek an adverse inference instruction and what evidence did they provide to support their allegations?
4. List the elements this court determined plaintiff needed to prove in order for defendant’s level of lack of preservation of evidence to justify an adverse inference instruction.
5. This court determined there were two avenues available to prove the relevance of allegedly spoliated information. What are they?
6. What is the state of mind required to show spoliation?
7. In your opinion, (a) was the court’s finding of gross negligence on part of the defendant and the order to compensate plaintiff for the costs and fees of filing the motion justified; and (b) should the court consider the level of technical competence of the attorneys and staff factor in motions such as these?