Hawai'i's law requires investigators to make their case before a judge in a closed, adversarial hearing where a defense attorney is appointed to argue against the wiretap. Prosecutors believe the hearings increase the risk that information might leak to the target and endanger informants or undercover agents.

"We use it next to never," Honolulu prosecutor Peter Carlisle said. "We're not going to risk putting people in danger."

Prosecutors have wanted expanded wiretap powers for the past several years, but state lawmakers, often citing Hawai'i's distinct constitutional right to privacy, have not agreed. This session, the Senate has passed new wiretap legislation that would end the requirement for an adversarial hearing, but the bill is in doubt in the House of Representatives.

"I'm just not sure," said Rep. Sylvia Luke, D-26th (Punchbowl, Pacific Heights, Nu'uanu Valley), the chairwoman of the House Judiciary Committee. "It's an issue I think we have to invest a lot of time in."

Wiretaps are considered the most intrusive law enforcement tool because of the potential for secretly capturing intimate and private information that may have nothing to do with criminal activity.

Federal law generally recognizes wiretaps as a last resort for investigators who have exhausted other means of obtaining information about serious crimes.

The federal law was expanded through the Patriot Act after the 9/11 attacks to include terrorism-related crimes and roving surveillance against terrorism suspects. But federal investigators still must obtain U.S. Department of Justice and court approval before using wiretaps.

According to the U.S. Courts, which compiles an annual report on wiretaps for Congress, state and federal wiretaps jumped by 25 percent in 2001 but have otherwise remained relatively stable over the past several years. In 2003, the latest report available, judges nationwide authorized 1,442 wiretaps — 578 for federal investigators.

In Hawai'i, U.S. District Court judges have granted 54 federal wiretaps since 2000.

Electronic surveillance, prosecutors and police say, can be invaluable in penetrating shadowy drug, gambling and organized crime operations. "I feel it is a very important tool," Attorney General Mark Bennett said.

Last September, in what was called "Operation Tap-Out," federal agents and Maui police used wiretaps to help break up a drug ring that apparently brought crystal methamphetamine — or "ice" — from Mexico to Maui and Lana'i. In October 2003, in "Operation Shave Ice," federal agents and Big Island police used wiretaps to interrupt "ice" and cocaine distribution rings on O'ahu and the Big Island.

The Senate bill eliminates the adversarial hearing but would still require investigators to show a judge probable cause for a wiretap, much like the process for getting a search warrant. The bill also requires investigators to show probable cause for mobile tracking devices or pen register and trap and trace surveillance — which is similar to caller identification features on many telephones.

Wiretap investigations can be expensive and involve a lot of manpower, so police say they would continue to partner with federal investigators even if they get new wiretap powers. Local investigators would likely use wiretaps on significant drug or gambling activity that falls short of federal interest.

"We want the option," said Capt. Evan Ching of the Honolulu Police Department's narcotics and vice division. "But it's got to be a really good case."

Public defenders and defense attorneys oppose the bill as both unnecessary and contrary to the state's history of preserving individual privacy. The Hawai'i Constitution was amended in 1978 to include a right to privacy that goes beyond the protections of the U.S. Constitution.

Keith Shigetomi, the defense attorney who appeared at the adversarial hearing for the sports-betting wiretap seven years ago, said the existing wiretap law is not very onerous. Attorneys are not representing the targets of the wiretap, he said, but are asked to look at the evidence and raise any concerns to the judge.

"It was not an unreasonable process," Shigetomi said.

Other defense attorneys also rejected the idea that attorneys would leak information they learn at the hearings to suspects, which would be illegal. Police, however, referred to a Honolulu attorney convicted in federal court last May of trying to smuggle "ice" into Halawa prison as an example of the security risk.

"It's a very weak excuse," said William Harrison, a defense attorney who also works with the American Civil Liberties Union of Hawai'i.

Harrison said prosecutors and police should have to explain why they have not tried to make the existing law work before the Legislature approves any new wiretap powers. The adversarial hearings, he said, force investigators to justify a wiretap before a defense attorney and judge.

"If you're telling the truth," Harrison said, "why wouldn't you want a third party to test it?"