A Maryland legislative panel yesterday ordered home detention firms to use electronic monitors to keep closer tabs on the convicted felons they supervise, in a move to regulate an industry that increasingly relies on random telephone calls to check on a detainee's whereabouts.

The panel's action came two weeks after a Capitol Heights woman was killed by a stray bullet that police believe was fired by a drug offender sentenced to home detention. Two random phone calls by a computer to the offender's home suggested nothing was amiss.

Maryland law does not proscribe how home detention firms are supposed to monitor the people they supervise. Under the current system, people ordered into home detention are required to make their own arrangements with a company. Many choose firms that offer the least restrictive and cheapest alternative, such as those that use computerized phone checks.

"The problem is defendants run the show," said Paul Kent, who runs Home Confinement Services in Rockville. "They shop from program to program."

Nearly everyone who testified at yesterday's legislative hearing in Annapolis, from law enforcement officials to several private monitoring firm operators such as Kent, said the surest way of monitoring people was through the use of electronic devices such as special bracelets worn by detainees. The bracelets are designed to send an instant signal to a monitoring station whenever the detainees leave their homes without authorization.

Even though the state relies on electronic monitoring equipment for some inmates released early from prison, state officials did not initially include a requirement for bracelets and other electronic equipment in a set of draft regulations submitted to lawmakers for their approval yesterday. Secretary of Public Safety and Correctional Services Stuart Simms said they believed the legislature had mandated them to provide the broadest range of options to judges and others.

But Sen. Christopher Van Hollen Jr. (D-Montgomery), who urged the new requirement, said "it baffles me" why it wasn't there to begin with. He said the rules should be tightened further to include a mandate on how quickly convicts -- who include violent offenders -- must retain home detention services after sentencing.

"If I were a judge, I would not send a violent offender to home detention because the system is too loose," Van Hollen said.

Del. James W. Hubbard (D-Prince George's), who also is an officer in the Prince George's County sheriff's department, long had sought tougher regulations on the industry. He said it was "less likely" that the new rules would have been strengthened without the publicity surrounding the slaying of Dona Elizabeth Ferguson, 40, a mother of five, as she hung curtains in her Capitol Heights home.

"I can't say if it would change anything, but the more technology, the less random chance there is" of a convict slipping through the net to commit a crime, Hubbard said.

Maryland's home detention system has been harshly criticized since a Prince George's man raped four women and robbed two others in 1997 while under the supervision of a private home detention company. A Prince George's grand jury found lax control of the industry and urged the legislature to strengthen regulation of the companies.

Last year, the General Assembly ordered the state to draw up new regulations, and yesterday's hearing was on the details of those regulations, which take effect Thursday.

In Maryland, six home detention firms provide services to about 500 people. Most of the home detention company representatives attending yesterday's hearing said they favored electronic monitoring but were being undercut in the marketplace by companies that used cheaper phone-check systems.

Home Tracking Inc., in Upper Marlboro, is one company that relies on phones. Jerry Romer, who runs the company, acknowledged that he is called the "Wal-Mart" of home detention services. Romer's company was supervising Kevin Arnes Boone, 21, at the time he allegedly shot Ferguson.

Romer defended using the cheaper phone system because it made home detention accessible to more people. Romer, a former probation officer, said he charges about $8 a day for the phone service but has accepted less. Electronic monitoring would require about $12 a day, which he said many people could not afford.

"We started with all [electronic bracelets], but the bills kept building" when many people couldn't keep up with their payments, he said. As for his price undercutting other companies that want to use electric bracelets, Romer said, "That's the American way."