The ACLU has filed a brief in support of a Baltimore man arrested after police spied on him and others without a warrant.
The ACLU has filed a brief in support of a Baltimore man arrested after police spied on him and others without a warrant.

The American Civil Liberties Union (ACLU) has filed an amicus brief asking a court to limit secret phone tracking and to force the government to produce information gathered by a stingray device that was being used to spy on one man but was later used to charge another.

Baltimore police, in an attempt to snare Derrick Smith in a fictitious murder-for-hire plot, had planted a cell phone with Smith, then used a stingray, without a warrant, to obtain data on that phone, which at one point was located in the apartment of Robert Harrison.

By cross referencing the phone's location and information related to Smith with the names of all residents living that address, police inferred that Harrison, who was subsequently arrested and is now awaiting trial on serious criminal charges, was Smith's accomplice.

“The chain of inferences leading to Harrison all stem from his possession of a phone, which the police did not learn through lawful search of his apartment with a probable cause warrant,” but rather through a device that secretly tracks phones, Samia Hossein, William J. Brennan Fellow at the ACLU Speech, Privacy & Technology Project, noted in a blog post Monday. “The government wants to insulate its use of a stingray with layers of excessive secrecy and expansive legal arguments.”

In support of Harrison's motions to the court, the ACLU brief, filed in U.S. District Court in Maryland, argues that by using the stingray device without a warrant, authorities violated Harrison's Fourth Amendment rights. 

Stingrays, the brief noted, are invasive, broadcasting signals that “penetrate the walls of homes and other constitutionally protected spaces,” pinpointing  locations with “extreme precision,” searching data “stored on phones,” affecting the privacy of third parties and disrupting phones in the area from making calls. 

“Use of a stingray constitutes a search within the meaning of the Fourth Amendment,” the brief asserted. “Assuming such searches are ever permissible… at a minimum they require a warrant based on probable cause.”

In addition, Hossein said the brief argued that the government didn't “properly obtain authorization to use the stingray” because it did not tell the judge, when applying for a court order, that it would be using a stingray.

 “The application the police submitted to obtain a court order (which is not the same as a warrant) for authorization to use the stingray was invalid because the application in fact requested permission to use a pen register/trap and trace device, which records the phone numbers with which a particular phone communicates,” Hossein noted.

The ACLU also claimed that the government, which is claiming law enforcement privilege, should be made to turn information about the stingray use over to the Harrison's defense. “The government is seeking to keep information about stingrays secret, but the reality is that it let the cat out of the bag a long time ago,” Hossein wrote.