Growing Presence in the Courtroom: Cellphone Data as Witness

Via NYTimes -

The pivotal role that cellphone records played in these two prominent New York murder trials this year highlights the surge in law enforcement’s use of increasingly sophisticated cellular tracking techniques to keep tabs on suspects before they are arrested and build criminal cases against them by mapping their past movements.

But cellphone tracking is raising concerns about civil liberties in a debate that pits public safety against privacy rights. Existing laws do not provide clear or uniform guidelines: Federal wiretap laws, outpaced by technological advances, do not explicitly cover the use of cellphone data to pinpoint a person’s location, and local court rulings vary widely across the country.

In one case that unsettled cellphone companies, a sheriff in Alabama told a carrier he needed to track a cellphone in an emergency involving a child — she turned out to be his teenage daughter, who was late returning from a date.

For more than a decade, investigators have been able to match an antenna tower with a cellphone signal to track a phone’s location to within a radius of about 200 yards in urban areas and up to 20 miles in rural areas. Now many more cellphones are equipped with global-positioning technology that makes it possible to pinpoint a user’s position with much greater precision, down to a few dozen yards.

To determine where a suspect’s phone was in the past — as in the Mallayev and Littlejohn cases — investigators use company records that show a phone’s approximate location at the beginning and end of a call.

To track suspects in real time, law enforcement officials must ask a phone company to “ping,” or send a signal to, a phone; for the effort to succeed, the phone must be turned on, though it does not have to be in use. The police can then use a vehicle with signal-tracking equipment to narrow down the location.

The frequency and ease with which law enforcement agencies access cellphone data to track people is difficult to assess. Civil liberties groups recently obtained data from the Justice Department through a lawsuit showing that in some jurisdictions, including New Jersey and Florida, courts often allow federal prosecutors to track the location of cellphone users in real time without search warrants.

Investigators seeking warrants must provide a judge with probable cause that a crime has been committed. But investigators often obtain cell-tracking records under lower standards of judicial review — through subpoenas, which are granted routinely, or through an intermediate type of court order based on an argument that the information requested would be relevant to an investigation.

In what would be the highest-level court decision on the issue so far, a federal appeals court in Pennsylvania is expected to rule this summer on whether search warrants are required for the most basic cellphone tracking data — the electronic footprints that cellphone users leave behind in company records, often without realizing it.

In March, Google announced that it would require search warrants before releasing GPS data that pinpoints the movements of customers who use its mapping applications — like Latitude, which lets people see where their friends are — on their phones.

But phone and Internet companies want Congress to clarify the laws so that they are clear about their legal responsibilities.

Civil libertarians do not oppose using cellphone surveillance to solve crimes or save people in emergencies, but they worry that the legal gray area is enabling it to happen without much scrutiny or discussion.

“The cost of carrying a cellphone should not include the loss of one’s personal privacy,” said Catherine Crump, a lawyer for the American Civil Liberties Union, which filed a lawsuit along with the Electronic Frontier Foundation after the Justice Department did not respond to a Freedom of Information request for data. Federal and local law enforcement officials argue that people who obey the law have nothing to fear from cellphone tracking.