A judge issued a warrant for Glen’s arrest based on a robbery and when police attempted to execute the warrant at the address listed on the warrant, the residents of that address gave the police a different address where they could find Glen. When the police knocked on the door of the new address, which belonged to Glen’s grandparents, Glen answered the door. The police immediately arrested Glen and read him the Miranda warnings. The police then entered the home and asked Glen’s grandfather, Mr. Brooks, if he owned the home. Mr. Brooks said that he did and that Glen lived with him but did not pay rent. Mr. Brooks gave the police permission to search Glen’s room. The police did not get Glen’s permission to search his room but he did tell the police which rooms he had slept in. In one of those bedrooms, the police found a backpack that had no clear indicators of who owned it (like a monogram or name tag) and was unlocked. The police searched the backpack and found evidence of the robbery. Glen admitted that the backpack was his and claimed that he found the evidence. the fourth amendment > The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized

how is this case related to the fourth amendment?

my teacher left a note saying that it is asking about how it is related to the fourth amendment not how it is related to the case