What is the test for a motion to suppress evidence in a civil case?

Defendant contends the trial court should have granted her motion to suppress because the officers initial detention of the three van occupants was unlawful and the evidence from her purse was obtained only through that detention. In reviewing the denial of a motion to suppress evidence, we accept the trial courts factual findings so long as they are supported by substantial evidence; we exercise our independent judgment to decide the legal question of whether the evidence was obtained in violation of the United States Constitution. (People v. Saunders (2006) 38 Cal.4th 1129, 1134.)