Electronic Surveillance
Because of the well-recognized intrusive nature of electronic surveillance—in particular wiretaps and room installations—not to mention the Fourth Amendment implications because of the Government’s use of these devices, in 1968, Congress “codified” the practice and passed the Omnibus Crime Control and Safe Streets Act. Collectively known as Title III—since that’s the section where the electronic surveillance provisions can be found—the statute gives law enforcement agencies the authority to seek court authorized wiretaps and install listening devices. For relevant provisions, as well as additional pertinent information concerning legal eavesdropping, interested parties should review Title 18, United States Code, Sections 2510 thru 2522.
Historically, while some federal law enforcement agencies used wiretaps as far back as the roaring twenties to collect evidence, in 1924, Attorney General Harlan Fiske Stone refused to allow the tactic stating he thought the practice was “unethical.” But not everyone shared Stone’s ethics or level of disdain. At the Treasury Department, the Bureau of Prohibition actively used wiretap evidence to prosecute bootleggers. Constitutionalists sought to eliminate the practice claiming wire intercepts violated Fourth and Fifth Amendment protections, but the Supreme Court disagreed. In Olmstead v. United States [277 U.S. 438 (1928)], the High Court ruled wiretap evidence was admissible because conversations were voluntary [not forced] and further intercepts were not considered a search and seizure under the Fourth Amendment.
But the controversy did not end until the Bureau of Prohibition was transferred to the Justice Department—creating an appearance problem. 
But because gang violence was on the increase, in 1931, Attorney General William B. Mitchell decided the technique could be used, but only in special limited circumstances. And he mandated wiretaps could not be initiated unless an appropriate Assistant Attorney General provided written approval authorizing the tactic.
Briefly speaking, Title III provisions provide law enforcement agents with explicit directives allowing them to seek a court order authorizing the intercepts. In seeking an application, agents must identify the crime problem as well as the investigative steps taken and exhausted to solve the problem. Agents must also identify suspects and locations where they expect to make an interception. And in the event authorities have information suggesting suspects have changed facilities in an effort to prevent law enforcement from making an interception, agents can seek permission for a “roving” wire. The most restrictive portion of the statute mandates all requests for intercepts must be submitted to the U.S. Department of Justice before an application can be submitted to an appropriate court seeking an order.
[Note: Information contained herein was taken from the Electronic Surveillance Manual prepared by the Office of Enforcement Operations, U.S. Department of Justice; and publication titled, “Electronic Surveillance and Civil Liberties,” prepared by the Office of Technology Assessment.]