After serving more than a year behind bars in New Jersey for assaulting a former girlfriend, David Goodell was transferred in 2010 to a sprawling halfway house in Newark. One night, Mr. Goodell escaped, but no one in authority paid much notice. He headed straight for the suburbs, for another young woman who had spurned him, and he killed her, the police said.

The state sent Rafael Miranda, incarcerated on drug and weapons charges, to a similar halfway house, and he also escaped. He was finally arrested in 2010 after four months at large, when, prosecutors said, he shot a man dead on a Newark sidewalk — just three miles from his halfway house.

Valeria Parziale had 15 aliases and a history of drugs and burglary. Nine days after she slipped out of a halfway house in Trenton in 2009, Ms. Parziale, using a folding knife, nearly severed a man’s ear in a liquor store. She was arrested and charged with assault but not escape. Prosecutors say they had no idea she was a fugitive.

After decades of tough criminal justice policies, states have been grappling with crowded prisons that are straining budgets. In response to those pressures, New Jersey has become a leader in a national movement to save money by diverting inmates to a new kind of privately run halfway house.

At the heart of the system is a company with deep connections to politicians of both parties, most notably Gov. Chris Christie.

Many of these halfway houses are as big as prisons, with several hundred beds, and bear little resemblance to the neighborhood halfway houses of the past, where small groups of low-level offenders were sent to straighten up.

New Jersey officials have called these large facilities an innovative example of privatization and have promoted the approach all the way to the Obama White House.

Yet with little oversight, the state’s halfway houses have mutated into a shadow corrections network, where drugs, gang activity and violence, including sexual assaults, often go unchecked, according to a 10-month investigation by The New York Times.

Perhaps the most unsettling sign of the chaos within is inmates’ ease in getting out.

Since 2005, roughly 5,100 inmates have escaped from the state’s privately run halfway houses, including at least 1,300 in the 29 months since Governor Christie took office, according to an analysis by The Times.

Some inmates left through the back, side or emergency doors of halfway houses, or through smoking areas, state records show. Others placed dummies in their beds as decoys, or fled while being returned to prison for violating halfway houses’ rules. Many had permission to go on work-release programs but then did not return.

While these halfway houses often resemble traditional correctional institutions, they have much less security. There are no correction officers, and workers are not allowed to restrain inmates who try to leave or to locate those who do not come back from work release, the most common form of escape. The halfway houses’ only recourse is to alert the authorities.

And so the inmates flee in a steady stream: 46 last September, 39 in October, 40 in November, 38 in December, state records show.

“The system is a mess,” said Thaddeus B. Caldwell, who spent four years tracking down halfway house escapees in New Jersey as a senior corrections investigator. “No matter how many escaped, no matter how many were caught, no matter how many committed heinous acts while they were on the run, they still kept releasing more guys into the halfway houses, and it kept happening over and over again.”

By contrast, the state’s prisons had three escapes in 2010 and none in the first nine months of 2011, the last period for which the state gave figures.

After The Times began its investigation last year, Mr. Christie adopted measures that his aides said would more tightly regulate the system. They said that because of these reforms, only 181 inmates had escaped in the first five months of 2012 — a 35 percent decline when compared with a similar period in 2009, before he took office.

But over several months of inquiries from The Times, state officials also revised downward the escape totals during Mr. Christie’s tenure.

Many inmates who escape from halfway houses are recaptured within hours or days, or turn themselves in after having second thoughts. But many remain at large for weeks, if not months, and are caught only after committing new crimes.

They have been arrested on charges of assaulting police officers, holding up a gas station and shooting strangers. They have been found selling drugs outside Newark schools and wielding a knife inside a Cape May bus station. Some have been caught as far away as Miami.

At least 85 inmates are currently at large, according to state records.

These men and women could be charged with felonies for escaping but typically are not. Usually, they are simply returned to prison to finish their original sentences. Some end up back at halfway houses.

The Times’s investigation encompassed more than 200 interviews with current and former halfway house workers, inmates, officials and others, as well as a review of thousands of pages of government, court and corporate records.

Mr. Christie, a Republican who took office in January 2010, has for years championed the company that plays a principal role in the New Jersey system, Community Education Centers.

Community Education received about $71 million from state and county agencies in New Jersey in the 2011 fiscal year, out of total halfway house spending of roughly $105 million, according to state and company records.

The company first obtained substantial contracts for its “re-entry centers” in New Jersey in the late 1990s, as state financing began increasing sharply. In recent years, it has cited its success in New Jersey in obtaining government contracts in Colorado, Pennsylvania and other states.

William J. Palatucci, who is the governor’s close friend, political adviser and former law partner, is a senior vice president at Community Education.

Mr. Christie himself was registered as a lobbyist for the company in 2000 and 2001 when he was a private lawyer, according to disclosure reports that his law firm filed with the state. In early 2010, he hired the son-in-law of Community Education’s chief executive as an assistant in the governor’s office, according to state personnel records.

And as United States attorney for New Jersey and then governor, Mr. Christie has often visited the company’s halfway houses and praised its work. The company has highlighted those visits in its publicity material.

“Places like this are to be celebrated,” Mr. Christie said in a 2010 speech at a 1,200-bed Community Education facility in Newark, a speech featured on the company’s Web site.

“A spotlight should be put on them as representing the very best of the human spirit,” he said. “Because as you walk through here, as I’ve done many times, what you see right before your very eyes are miracles happening.”

Mr. Christie would not be interviewed for this article.

In a statement, his spokesman, Michael Drewniak, said Community Education had been “associated with public contracting in New Jersey going back no less than 18 years to the administration of Gov. James Florio and every governor, Democrat or Republican, since that time.”

“The suggestion of favoritism is defeated by the demonstrable fact that none has occurred,” Mr. Drewniak said.

Mr. Drewniak emphasized that Mr. Christie had had a deep interest in improving drug treatment and other services for prisoners since his days as a county lawmaker in the 1990s.

Community Education said it had developed a highly successful model of “community corrections” that had improved the lives of hundreds of thousands of inmates across the country. It said the rate of escapes at its halfway houses in New Jersey was “staggeringly low,” given the many people who go through the system. And it blamed other halfway house operators for allowing escapes of inmates whom Community Education had first handled.

“To focus on walkaways from halfway houses would be to report on only part of the story and not include the positive outcomes for the majority of offenders who complete a halfway house program without walking away,” the company said in a statement.

Roughly 10,000 prison inmates and parolees a year — equivalent to about 40 percent of the state prison population — now pass through the system of halfway houses; most spend time at a Community Education halfway house.

But regulation by a patchwork of state and county agencies has been lax. The state comptroller determined last year that there were “crucial weaknesses in state oversight.”

The Christie administration began fining Community Education and other operators for escapes only in April, eight months after The Times undertook its investigation.

The Legislature has not scrutinized the system either.

Assemblyman Charles Mainor, a Democrat and police detective who is chairman of the Law and Public Safety Committee, was asked for his estimate of how many people escaped from halfway houses in 2011.

“I have heard of no more than three,” he responded.

According to state records, the number was 452.

Assemblyman Sean T. Kean, a Republican, said of the escapes, “It’s not really a problem.”

“It’s a cheaper way of doing business,” he said of the system, “so that’s why it behooves us to use that option.”

‘The Greatest Times’

Viviana Tulli stuck out her tongue in family photos. She threw water balloons at friends. Once, to make her sister laugh, she took a running jump and dived into an eight-foot bush in front of their home in Garfield, N.J., a suburb of New York.

She had worked at a pet store — few animals were ever loved more than her Chihuahuas, Mikey and Hennessy — but had not settled on a career.

She was 16 when she met David Goodell, who was a decade older and claimed to be affiliated with the Bloods gang.

“Everybody had a bad feeling about him,” said Martha Galan, now 22, a close friend, who often shared secrets with Ms. Tulli on her family’s porch.

Mr. Goodell wore baggy jeans and oversize sweatshirts that swallowed his 140-pound frame. He had the temper and swagger of an insecure man trying to act tough.

He was arrested in 1997 for committing three robberies and then briefly spent time in Talbot Hall, a Community Education halfway house. In 2003, he was released on parole.

He worked as a warehouse packer and a truck driver but was arrested again in 2008, after he pinned a former girlfriend to the ground and threatened to kill her if she did not give him money.

While he was in custody on those charges, his romance with Ms. Tulli took off. He wrote her dozens of long letters addressed to “Supergirlfriend” or “Princess.” He promised her a future far from New Jersey.

“The times that are to come with you and I are gonna be the greatest times of both of our lives,” Mr. Goodell wrote.

His letters were filled with meticulous drawings shaded in pinks and blues — the two of them smiling in matching clothes, a tearful boy holding a flower for her.

Ms. Tulli told her parents he was just a pen pal, but she enjoyed the attention. She kept his letters in a folder hidden in her bedroom. She visited him and sent him photos of herself.

In September 2009, at the time of Mr. Goodell’s sentencing, Judge Nestor F. Guzman, of Superior Court in Passaic County, wrote that there was a “risk that defendant will commit another offense,” according to his case file.

Six months later, after 16 months behind bars, Mr. Goodell was paroled and transferred to a Community Education halfway house.

The company’s halfway houses, like others in the system, have varying degrees of security. Some allow inmates to leave on work release, and those facilities tend to have the most escapes. Other halfway houses are locked down, but restrictions are sometimes sidestepped.

Mr. Goodell was sent to Logan Hall, which in recent years had one of the highest totals of escapes in the halfway house system — 185 from 2009 through 2011, according to state records. There, he used a cellphone to call Ms. Tulli constantly. Inmates are not allowed to have them, but cellphones, like drugs and almost anything else, were readily obtainable in Logan, former workers and inmates said.

Finally, Ms. Tulli, who was 21, ended contact.

That set him off.

Mr. Goodell had often boasted to her that in prison he pretended to be ill to get privileges. On Aug. 29, 2010, at Logan Hall, he did so again, to seem as if he had a seizure, prosecutors said.

A low-level Community Education worker escorted him to University Hospital in Newark.

Many Community Education workers are paid little more than minimum wage and have previous job experience that amounted to operating a convenience store register. The worker, like all halfway-house employees, had no authority to restrain Mr. Goodell.

At the hospital, he slipped away.

He persuaded Ms. Tulli to meet him nearby in the middle of the night. Before she left, she poked her head in her mother’s bedroom to say goodbye and wish her a happy birthday. Her mother turned 60 the next day.

At 1:11 p.m., the police received a phone call that a man covered in blood was standing in the Ridgefield Park High School parking lot.

It was Mr. Goodell.

When the police arrived, Mr. Goodell jumped behind the wheel of Ms. Tulli’s car and sped away. After a chase, he was cornered in a cul-de-sac.

Officers found Ms. Tulli’s body in the passenger seat. She had been suffocated. Mr. Goodell, who had slashed his wrists, was charged with murder. The case is pending against Mr. Goodell, who is now 32.

In the days after the killing, Ms. Tulli’s relatives took solace in announcements by the Christie administration and Community Education that they would conduct separate inquiries and consider adopting reforms.

“Use my sister as an example,” her older sister, Stella Tulli, recalled thinking. “Security needs to be tightened in all aspects. There’s money being funded, and there’s no accountability.”

And so they waited, hopefully, for the findings.

A Growth Industry

When the system was created, the large halfway houses were intended to help low-level offenders toward the end of their sentences. Inmates would be housed in dormitory-style rooms and receive drug treatment, job counseling and other services.

Many experts praise the halfway-house model, saying that if facilities are well managed, inmates are less likely to return to crime. State officials and Community Education credit the system with helping to reduce the state’s recidivism rate, as well as its prison population, which fell to 25,000 in 2010 from 30,000 in 2000, federal data show.

Community Education offered a tour of one of its facilities, the 500-bed Talbot Hall, showing off orderly group counseling sessions and tidy living spaces.

In interviews of inmates who had been in the company’s halfway houses, some spoke highly of its programs.

“It taught me how to have patience, how to keep moving forward and stop looking back,” said Sal Hemingway, 41, who was imprisoned on murder charges in the 1990s and was in a Community Education facility last year.

The financial incentive is also clear. The state spends about $125 to $150 a day to house an inmate in a prison. The corrections, parole and other government agencies in New Jersey pay roughly $60 to $75 per inmate per day to operators of halfway houses, including Community Education, based in West Caldwell, N.J.

But as the system has grown, the percentage of New Jersey inmates convicted of violent crimes but lodged in halfway houses has been rising, to 21 percent now from 12 percent in 2006, according to state statistics. Their ranks currently include dozens of people serving time for murder, and hundreds convicted of armed robbery, assault or weapons possession — some of whom escaped.

At the same time, the state acknowledges that it has never examined whether the system helps inmates. Last year, the Christie administration commissioned a three-year study. Community Education has financed its own research that it says shows the success of its programs.

Mr. Christie has also established a task force to coordinate the state’s efforts intended to help inmates as they leave prisons.

Over all, New Jersey’s system has about 3,500 beds in two dozen or so halfway houses. Community Education runs six large facilities, with a total of 1,900 beds for state inmates and parolees, along with others for county and federal inmates.

Community Education’s leading role in the system means that the company had been responsible at one point for many of the inmates who escaped.

All inmates transferred to halfway houses by the Corrections Department are required to first spend about two months at a Community Education halfway house that serves as an assessment center. (Parolees generally do not.)

The company says it evaluates the inmates and recommends to the state which ones are low-risk and unlikely to escape. Those inmates are then transferred to other halfway houses — run by Community Education or other operators.

Thus, though facilities run by a nonprofit organization, the Kintock Group, accounted for nearly half of the escapes in recent years, according to state records, many of those inmates arrived at Kintock after first being deemed low-risk by Community Education halfway houses. From 2009 through 2011, about 16 percent of escapes were from Community Education halfway houses, according to state data. Another 43 percent were inmates who had been evaluated by Community Education halfway houses and then escaped from others.

Robert Mackey, a senior vice president at Community Education, said in an interview that the company had excellent security and strove to prevent escapes by providing therapy and other services to discourage inmates from leaving.

“If somebody was climbing over that fence right now, our recourse would be to notify the authorities,” Dr. Mackey said. “We could not physically take them off the fence to restrain them from escaping.”

He added, “The staff here are not law-enforcement officers.”

The company said a better way to measure its security was to examine how few inmates escaped, given the tens of thousands who went through its facilities in recent years. It said that by its calculation, since 2005, 0.53 percent of inmates from the Corrections Department and 3.3 percent of inmates from the Parole Board had escaped.

Dr. Mackey said the company could not be held responsible for inmates who had entered the halfway house system through its facilities and then escaped from others. “We certainly didn’t cause the escape,” he said. “The other halfway houses also have to look at, what are they doing.”

David D. Fawkner, chairman of the Kintock Group, said he was surprised to learn of the frequency of escapes from Kintock halfway houses.

“The number does take me back a little bit,” he said.

Mr. Fawkner said halfway houses served a difficult population moving into the community.