Maryland Gov. Martin O'Malley planned to unveil a new cellphone security system Friday at the Baltimore City Detention Center.
The technology automatically blocks calls from all cellphones inside the building, except a small number of phones assigned to employees. It also allows any phone to call 911.
It's a misdemeanor to smuggle a cellphone into a Maryland correctional facility. In 2007, an inmate used a cellphone to arrange the killing of a Baltimore County witness.
The system has been up and running since Dec. 30, said Rick Binetti, a state corrections spokesman. The facility has been tweaking it since then.
O'Malley's proposed budget for the next fiscal year includes money to install similar systems at two more Baltimore corrections facilities. The Metropolitan Transition Center already has one in place, Binetti said.
Binetti said Maryland's corrections facilities started having a cellphone problem in the early 2000s as the devices became smaller and easier to smuggle in. The state started cracking down in 2007, when it confiscated 741 phones from inmates. It took 1,658 in 2009, but the problem has decreased since then, he said. Last year, guards collected fewer than 1,000 phones.
The state tried several years ago to get permission to jam all cellphone use in the jail, but the federal government does not allow state facilities to do this, Binetti said.
It settled on a "managed access'' system instead, which blocks calls selectively, based on the number the call comes from.
The Hanover company Tecore Networks designed and built this system. It installed the first system at the Metropolitan Transition Center in 2012 and tested it in 2013, Binetti said.
Binetti said assaults against corrections staff have dropped by 60 percent since the state started enforcing cellphone policies in 2007.