Mapp started out in state court with her case. She then brought it to the Supreme Court and lost her final case. (Writ of Certiorari)
After Mapp's case the judges had a Conference. This is where they came to the conclusion that she's guilty.
"In Mapp v. Ohio (1961), for example, the American Civil Liberties Union filed an Amicus Brief that argued for the exclusion from a criminal trial of evidence seized without a search warrant."
Oral Arguments for the case were given by A.L. Kearns and Bernard A. Berkman.

Ohio won the case vs. Mapp. The Majority decision: "Our decision, founded on reason and truth, gives to the individual no more than that which the Constitution guarantees him, to the police officer no less than that to which honest law enforcement is entitled, and, to the courts, that judicial integrity so necessary in the true administration of justice." The Concurring decision: "the Fourth Amendment does not itself contain any provision expressly precluding the use of such evidence, and I am extremely doubtful that such a provision could properly be inferred from nothing more than the basic command against unreasonable searches and seizures."
This is a landmark case because it had a significant impact on how to handle Fourth Amendment rights such as in this case the right to privacy in your own home. It might have even effected the way police handle search warrant's and their accuracy in doing so.

The Case

Dollree Mapp who lived in Cleveland, OH was arrested for having pornography photos, videos and books in her house. The police only found this after breaking into her house to search for a suspected bomber. The first time the police came she would not let them in because they had no search warrant. They came back with a piece of paper claiming it was a search warrant; they quickly flashed it in front of her instead of letting her examine it. Later she found out it wasn't a real search warrant. After the police entered her house they dragged her up the stairs to search her bedroom. Finding nothing, they searched her basement to find all of the illegal photos, etc. After this the police handcuffed and arrested her and took her to jail. Mapp soon took her case to the Supreme Court stating her right to the Fourth Amendment "The right of the people to be secure in their persons, houses, papers effects, against unreasonable searches and seizures, shall not be violated, and no warrants shall issue, but upon probable cause." Mapp did not win this case because the Fourth Amendment doesn't specify when a search is "unreasonable", especially when other illegal evidence is found, like in Mapp's case.