Police are required to obtain a search warrant to conduct a drug investigation.
The problem is that they often do not.
In a recent study, police in Massachusetts conducted more than 1,500 drug tests over a five-year period, and none of them were turned up.
Police in New York City conducted more testing, but not nearly as many, and turned up less drug evidence.
In Washington, police officers who conduct drug testing do not have to obtain warrants.
They can conduct their own search without a warrant, even if the suspect is not in custody.
In the Washington case, prosecutors said police found marijuana and a gram of cocaine in a house where they had served a warrant for a drug case.
The officers then searched the house without a search and found a small amount of marijuana and cocaine, according to the charges.
The police officers were cleared of criminal charges in November, but prosecutors say the officers had not received a search-warrant approval from Washington’s Police Department, which oversees police agencies across the state.
The Washington case was the first of its kind in the country.
In a statement, the city said that while it does not have a formal policy on warrantless searches, the department will conduct an internal review to determine whether officers violated department policies.
“The department will take appropriate action if necessary, including seeking an investigation by the Washington Attorney General’s Office,” the statement said.