What is the test for a vehicle impoundment and inventory search?

Impoundment without probable cause is lawful only conducted "on the basis of something other than suspicion of evidence of criminal activity." (Colorado v. Bertine (1987) 479 U.S. 367, 375.) Inventory searches of impounded vehicles are exempt from the warrant and probable cause requirements so long as they are not to further a criminal investigation, but "to protect an owner's property while it is in the custody of the police, to insure against claims of lost, stolen or vandalized property, and to guard the police from danger." (Id. at p. 372.)

Defendant did not specifically challenge the supposed impoundment and inventory search, but focused on the detention of the automobile. The inventory search issue is a separate constitutional issue from the detention issue. The rule is that defendants cannot assert federal constitutional errors for the first time on appeal. (People v. Smithey (1999) 20 Cal.4th 936, 995.) The defendant must specify the particular ground as to why a warrantless search and seizure was unreasonable. (People v. Williams (1999) 20 Cal.4th 119, 130.) The grounds asserted by defendant on appeal governing the inventory search were not raised before the trial court and are therefore forfeited.