Private Security Guard Searches

I have received many questions from drivers about the 4^th Amendment and if it protects from a private security guard search. The 4^th Amendment to the U.S. Constitution stops the government from searching and seizing your property without probable cause. If the government wants to conduct a search, a warrant can be issued specific to the items to be searched as well as their location, and what may be seized.  There are several exceptions that allow a warrant-less search (stop and frisk, search incident to a lawful arrest, plain view doctrine, hot pursuit, automobile, and consent.)
 
Anyone who is acting on behalf of and under the guidance of the government becomes an agent of the government and as such is covered by the 4^th Amendment.  The government can’t have someone do something for them they could not do for themselves.  This prevents the government from abusing your rights.
 
So, does this Amendment cover security guards that do not act for or under the guidance of the government?  No. Security guards are not prevented by the 4^th Amendment from entering your truck on their employer’s property.
 
When entering someone’s property, like a warehouse dock, you become an invitee and the property owner has certain responsibilities to its guests.  One is to protect guests from known dangers on the property.  Employers have the obligation to protect their employees while they are at work.  An employer can protect their employees by limiting entry of weapons or drugs on the property.  A notice should be posted that weapons and drugs are not allowed on the property and all vehicles and/or persons on the property are subject to searches.  Yes, they can do that. When notified of a possible search and you enter the property willingly, you are agreeing to the possibility of a search.
 
However, without a visible notice posted by the shipper and the opportunity to decline a search before entering the property, you could reasonably file a police report for trespass against the guard.
 
The difference between the government and private security guards is that the government can force a search, the security guards cannot.  The security guard can’t put you in jail or give you a fine for failing to allow them to search you or your truck.  They can deny entrance onto the property if you deny permission for the search.