A template of that voice is installed on a host computer equipped with a telephone checking system.
The youth is informed of the rules of the program and signs a consent form, Carnell said.
When an automated call comes in, the youth must say 22 words so the voice template in the computer can be checked against the voice, Carnell said.
Bob Weaver, director of the Department of Juvenile Services for Washington County, said the teenager's entire household becomes involved in the program.
The family must eliminate features on the home phone, such as call waiting or call forwarding, Carnell said.
"No cordless phones can be used," he said. "And the same phone must be used each time an automated call comes in."
That means the teen might have to run downstairs in the middle of the night if that one phone is the kitchen phone, Carnell said.
Other family members must not monopolize the telephone or the teen on detention will have some explaining to do, he said.
"The computer will call three times before it pages the community detention worker," Weaver said. When she is called, a personal visit is the next step.
Melissa Reynolds is the community detention worker for Frederick and Washington counties. So far she has only three clients.
She said she already has found one of those three in violation of the home detention rules.
"I went to his school to proctor an exam when I noticed alcohol on his breath," Reynolds said.
Those who violate the rules are sent to Noyes Detention Center in Rockville, Md., Weaver said.
Weaver said no violent teens will be released on community detention.
Sandra Werther, who works with the community detention program in Ellicott City, Md., said the success rate is 80 percent statewide.
That rate indicates youths who incur no violations and show up for court appearances while in the program.
Any teen hoping to go into the program must have a telephone, Carnell said.
"If they don't have a phone, we will install one - a totally restricted phone that won't even call 911," Carnell said.
The teens on the program don't have to pay for the service.