Yes, but the Court can only order urine drug testing. Although often times parties to a divorce case will agree to hair follicle testing, the Court is not supposed to order hair follicle testing.
Family Code section 3041.5 is the direct authority for a court’s ability to order drug testing. However, it contains an important limitation: If substance abuse testing is ordered by the court, the testing shall be performed in conformance with procedures and standards established by the United States Department of Health and Human Services for drug testing of federal employees. These procedures and standards do not presently include hair follicle testing and so a Court cannot order it over a party’s objection.
You can cite this case to the Court if the Court tries to order hair follicle testing– Deborah M. V. Superior Court (2005) 128 Cal.App.4th 1181, in this case the Appellate Court found that only urine drug testing is permissible.
As a practical matter, California Family Courts order urine testing. The effectiveness of urine testing is limited because traces of different substances remain in body for differing amounts of time – traces of drugs remain in hair much longer often as long as 90 Days.
In many cases, hair follicle testing will be ordered where both parties agree or stipulate to it, which is in fact quite common. In many cases a Judge will ask the parties if they would be willing to take a hair follicle test, and if they or their attorney agrees then the Court will order the test.
Under Family Code Section 3041.5 A positive test alone shall not be basis for an adverse custody determination. Test results are confidential and are for use only in the family law proceeding. If the other party releases the results they could face sanctions for violating your privacy.