chicken wings
US police forces are breaking out Stingray mobile phone trackers to detect robbers iStock

Continued investigations into how local US law enforcement uses the controversial mobile phone tracking technology Stingray has uncovered the fact that some police departments are using it for non-essential cases, such as catching a guy who stole some food from a delivery driver.

A report into how police in Washington, Baltimore and seven other countries use Stingray by Capital News Service has uncovered the fact that police in Annapolis, Maryland used the mobile phone trackers to help locate targets in 17 cases since it invested in the equipment in late 2011.

When Annapolis Police were stuck trying to figure out who robbed a Pizza Boli's delivery person of 15 chicken wings and three submarine sandwiches worth of a total of $56.77 (£39), it seems they obtained a court order to approve a warrant to use a Stingray to track the Stephon Summer's phone to locate him, which is a far cry from the repeated claims by government agencies that the technology is "vital to the war on terrorism".

"He's not a terrorist, he's just a kid from the neighbourhood," said Prince George's County public defender Jason Ricke. "The main problem is that the police may be doing something illegal and we have to use mental gymnastics to try and uncover these secret aspects of an investigation that are never written down and turned over to us. The police may be violating our clients' rights and we will never know it."

Judges discarding evidence gathered via Stingray

In another case in Baltimore, police were seeking a man for burglary and robbery charges, and they arrested Deon Batty, who was carrying a stolen mobile phone from a 77-year-old, as he stepped off a bus.

In court, the police refused to say how they were able to arrest Batty, saying that it was a Homeland Security issue, which led the Baltimore City Circuit Court judge to throw out the phone evidence, but a city log proved that the police used Stingray to track and locate Batty.

In the end, the phone evidence was thrown out and Batty was given a deal, pleading guilty to a second- degree assault charge instead.

"There may be good reason to withhold details of individual pending investigations, but wholesale secrecy of this kind prevents the public from assessing whether use of invasive surveillance equipment in local communities is necessary or wise, and whether appropriate policies are in place to ensure judicial oversight and protect privacy," Nathan Freed Wessler, a staff attorney with the American Civil Liberties Union wrote in a blog post.

"One wonders what the real purpose of this secrecy about secrecy is. Perhaps the State Police are feeling a bit sheepish that they signed an agreement promising to withhold basic information about Stingray use not only from the public, but even from judges and defense attorneys in criminal prosecutions."