ALBANY — Virtually erasing its 1993 landmark ruling on electronic surveillance, the Court of Appeals held yesterday that pen registers may be installed on phone lines without a wiretap warrant under a 1988 amendment to the Criminal Procedure Law.
Pen registers, which record numbers dialed on a telephone line, are used in nearly all wiretap investigations to develop the probable cause needed for an eavesdropping warrant. Most pen registers also can be converted to monitor conversations after the warrant is obtained, but until six years ago police were allowed to install the device itself based on a showing of reasonable suspicion.
