WASHINGTON (AP) - The Supreme Court said Monday it will decide whether police may enter a home without a search warrant when an informant already is inside and sees evidence of a crime.

The case from Utah also will test whether the officers who conducted the warrantless search may be sued by the person they arrest.

Six years ago, an informant contacted police to tell them he had arranged to purchase drugs from Afton Callahan at Callahan's trailer home.

Wearing a microphone provided by police, the informant entered the trailer, made the deal and signaled police. They entered the trailer without a warrant and arrested Callahan for possession of methamphetamines.

Utah courts ruled that the evidence that was seized from Callahan's home could not be used against him. Other courts have allowed prosecutions to go forward under similar circumstances.

Callahan then sued the officers for violating his constitutional rights.

A federal judge ruled that the officers could not be sued because there is disagreement in the courts over whether the search is illegal.

The 10th U.S. Circuit Court of Appeals in Denver said the lawsuit could proceed because the officers should have known that people have a right in their homes to be free from unreasonable searches and seizures.

The case is Pearson v. Callahan, 07-751.