What is the burden of presenting evidence to support a section 1021.5 fee claim?

Defendants had the burden to present evidence to support their section 1021.5 fee claim. (Bui v. Nguyen, supra, 230 Cal.App.4th at p. 1365.) But they presented no evidence at the hearing on the attorney fee motion. The trial court found "these issues were not litigated." It said that because plaintiffs "had not sustained their burden to demonstrate a public nuisance, the court was not addressing these issues." Consequently, there was no proof regarding this alleged impact of the litigation. Moreover, the court also found the gangs' activities constituted a "nuisance" to the community--a finding that does not enhance property values or the City's reputation.