Final answer:
The detective can legally access the computer either by obtaining consent to search from the parents or by obtaining a search warrant from a judge, as protected by the Fourth Amendment.
Step-by-step explanation:
To legally gain access to the computer in a situation where there is a suspicion of criminal activity, a police detective has several options. However, not all are applicable in every situation. Given the scenario, the most appropriate and legal method for the detective to access the computer would be to obtain consent to search from the parents (Option C) or obtain a search warrant from a judge (Option A).
According to the Fourth Amendment, the right of people to be secure against unreasonable searches and seizures is protected, and no warrants shall issue, but upon probable cause. A warrant must be issued by a judge, supported by oath or affirmation, and particularly describing the place to be searched and the persons or things to be seized. This is the standard protocol unless there are exigent circumstances or the owner consents to the search.
Legislation like the USA Patriot Act does allow for expanded government surveillance powers, particularly concerning national security and terrorism cases. However, critics argue its use often extends beyond its intended scope. The Computer Security Act is not mentioned as an allowance for warrantless seizure of individuals' property. It is important to remember that obtaining a warrant or consent ensures that any evidence found is admissible in court, and it protects the rights of the individuals involved.