Thousands of undocumented immigrants from Central America remain free in the U.S. until their court hearings.
Many people think they're just roaming around.
But the federal government is keeping tabs on some of them with technology currently being used on at the local level on people awaiting court dates.
"They know exactly where I am at," said Susan, who asked that her real name or picture not be used because she is facing a drug charge.
But instead of sitting in jail and waiting for her case to go through the court system, she wears an ankle monitor so her probation officer can keep tabs on her around the clock.
"It's GPS and they know where I am at all times," Susan said.
"It just gives me an opportunity to remain free and be able to maintain employment and handle my affairs," Susan said. "I do feel like it is showing the court I am a productive member of society."
Susan is one of roughly 1,800 pre-trial defendants in Maricopa County participating in an ankle bracelet program that proponents say reduces the jail population and saves taxpayers money.
"It's much cheaper to have somebody out on a bracelet than putting them in custody," Taylor Pile of the state Adult Probation Department said.
If the person wearing the bracelet is not where they're supposed to be, isn't home on time or starts tampering with it, an audio alarm is activated: "Report to the office immediately."
The program has been so successful on the local level, the federal government is expanding the number of ankle monitors given to illegal immigrants.
Immigration officials said they just don't have enough detention facilities to hold the latest wave of illegal immigrants who come to the U.S. from Central America.
But instead of just releasing them and telling them to appear in court, immigration officials have given the ankle monitors to many of them.
Officials said the ankle bracelets are extremely effective in getting people to appear in court.
"The compliance rate with those who are being monitored with electronic ankle bracelets can be as high as 90 percent," said Amber Cargile of the U.S. Immigration and Customs Enforcement.
The latest statistics show roughly 7,400 illegal immigrants are currently wearing an ankle bracelet, 314 of them in Arizona.
The cost is about $5 day to monitor someone with an ankle bracelet, compared with $118 a day to keep them in jail.
They are worn only by adults.
Individuals wearing the ankle bracelets say it's better than being locked up.
"It doesn't hurt at all," Susan said. "There's no inconvenience. It's comfortable. I have no issues with it."
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