In Times Square one day last week, dozens of distraught Dominicans obstructed foot traffic, demanding help from their consulate and their president, and sobbing as they held up pictures of husbands, sons, and fathers in detention or exiled for life from America. Every major Spanish-language print and broadcast outlet in the New York area recorded the event. Tourists stopped and stared.

Hoisting signs reading “Basta Ya” and “Deportations are a passport to family destruction,” the demonstrators voiced criticism growing ever deeper within New York’s Dominican community: that America’s widespread mandatory deportation of immigrants with criminal records, many of them nonviolent and many of them legal residents, is causing more harm than good.

“When it’s a violent criminal, or a violent crime, we as a community welcome these people be deported. We welcome that the U.S. is not going to tolerate any criminal abuses as such, but there are other crimes that we believe shouldn’t be punishable by deportation,” the president of Hispanics Across America, Fernando Mateo, said in a telephone interview, citing as examples “jumping a turnstile might get you deported, carrying a weapon can cause you deportation.”

Mr. Mateo, an businessman and top Bush fund-raiser who spoke at the Republican National Convention, said he sent a letter to Governor Pataki about six cases of sympathetic deportees. One was a grandmother who said she did not realize her nephew was using a rented room in her home to deal drugs. One was a husband caught with a weapon he had bought to protect his family. One was a middle-aged man convicted in his teens of drug possession.

The governor, Mr. Mateo said, responded that it was not an issue he was in a position to address at the time. That was a grave disappointment to Mr. Mateo.

“There are so many cases like this that are just not fair, not right. You can find them by the tens of thousands just in the Dominican community,” Mr. Mateo said. “In particular, we’re hurt by the deportations of people who have committed crimes in the past, did their time, straightened their lives out, and all of a sudden Bill Clinton signs this law that is retroactive.”

Mr. Mateo was referring to two laws Congress – controlled at the time by Republicans – passed in 1996, which broadened the scope of crimes subject to mandatory deportation.

The reason for Mr. Mateo’s complaint about the retroactivity is that even if, for example, a legal permanent resident with family here had pleaded guilty as a teenager, long before 1996, to a charge of drug possession, he could still be subject to mandatory deportation.

One result is that many immigrants from the Dominican Republic will travel home for a visit and never be allowed to legally reenter this country. Others will complete sentences here and be sent straight to a jail or detention center in Pennsylvania or New Jersey, or frequently in Louisiana. There they are held with no legal recourse until they are flown back to Santo Domingo, the Dominican capital, escorted by federal marshals.

According to a former special agent in New York and Miami for the Drug Enforcement Agency, Tom Cash, the laws were necessary because of the high levels of violence and drug sales he saw, particularly in the Dominican community, in the 1980s and 1990s.

“I think the line-drawing is really the word ‘felony,'” said Mr. Cash, now a consultant at the security firm Kroll International. “It’s something you do yourself. It’s not done to you. When you commit the felony it is your fault, and you and the country from which you originated should be responsible.”

Most deportations are of people convicted of “aggravated felonies,” a term that applies to some nonviolent offenses, including shoplifting. An offender also can be deported for an act of “moral turpitude,” which can be a misdemeanor conviction that involves an intent to defraud, such as jumping a subway turnstile.

In New York, no population has felt the effect of the 1996 laws as widely as the Dominican community, the city’s largest immigrant group, from which nationally more than 20,000 criminals have been deported.

Beginning today at the John Jay College for Criminal Justice is the first conference to investigate the negative repercussions of the removal of roughly 500,000 criminal aliens in recent years. The conference, organized by John Jay and the Legal Aid Society, is bringing together 300 academics, lawyers, and community organizers to discuss the effects of criminal deportations, such as the strain on the welfare system and dividing families, detention far from New York, the burden on receiving countries, and illegal re-entry.

An organizer of the October 13 march at the Dominican consulate, Raquel Batista, said she thought the increased activism around the issue was an indication of a change in attitudes. In the past, Dominican families here were more apt to conceal a relative’s forced departure like a dirty secret. Now, many in the Dominican community are seeking public attention for the plight of their loved ones, and those who stay behind.

Ms. Batista is director of the Northern Manhattan Coalition for Immigrant Rights, and Dominican immigrants with family members who are detained or deported frequently approach her for help. “Everyone in the Dominican community knows someone who has been deported,” she said. “They have been cut off from their New York families and communities, but not forgotten.”

With the deportee frequently the primary breadwinner in a family, Ms. Batista said, “The effect is great both psychologically, emotionally, and economically, over here and over there.”

Melissa Montanez, 34, is still reeling from the deportation in June of her fiance, Julio Suriel. At the time, Ms. Montanez was pregnant with their daughter.

The son of a naturalized American citizen, and a permanent legal resident himself since he arrived at age 11, Suriel, 38, thought he could not be deported. But as a felon who was incarcerated for two-and-a-half years on cocaine charges, he should have been deported even earlier – as soon as he completed his prison time.

Suriel was mystified at being held at 26 Federal Plaza when he went to get a new green card last October. After a day of waiting, he was told to return the next day. When he did, Suriel had handcuffs slapped on him.

He was transferred to a jail in Pennsylvania, and then to a detention center in Louisiana. Rather than accepting deportation, Ms. Montanez hired a lawyer to contest the order and paid the attorney $2,000. The lawyer didn’t tell her that under the 1996 laws, because her husband was a non-citizen convicted of an aggravated felony, he was subject to mandatory deportation, with little avenue for legal appeal.

“We have taken away that step of allowing the judge to determine whether it’s right for a person to deport, which is one of the reasons we have all these cases of people who are being deported for crimes that were trivial in relation to the consequences of deportation,” a Legal Aid lawyer, Bryan Lonegan, said. “You have this situation which is pretty desperate of tens of thousands of people being arrested, detained, and ineligible for relief.”

Even in those rare cases in which the deportation order is unwarranted under the law, many of the immigrants are nevertheless deported, according to Mr. Lonegan, who is one of the few defenders providing free legal services to New York detainees. Translators are available for the defendants in the federal immigration court, but because the proceedings are classified as civil rather than criminal, defendants are not guaranteed an attorney, and many cannot afford one.

Even with a lawyer, Suriel was sent back to the Dominican Republic after seven months in detention.

“I feel like my life was taken away in an instant,” Ms. Montanez said, stopping to apologize for her tears. “It’s like you think you have it all, and you don’t realize in a flash everything can end.”

As is often the case with the spouses of deportees, Ms. Montanez did not follow her husband, for financial and familial reasons. She has two adolescent children in America from a previous marriage, and Suriel has three. Roughly half of the deportees leave children in America, according to most estimates. While she agonizes over the idea of her infant daughter growing up without a father, Ms. Montanez, an American citizen, has never lived in the Dominican Republic, and with its unemployment rate approaching 20% she worried she’d be unable to find a job there.

“It’s tearing families apart,” Ms. Montanez said. “It’s a very touchy subject. I don’t wish this upon nobody.”

Left alone in New York, without Surial’s income, she has had to file for bankruptcy protection. Her fiance, a building supervisor, is unemployed in the Dominican Republic, where deportees face strong prejudice, and is surviving on money sent from his brother in America.

Stories like Ms. Montanez’s are increasingly common, according to John Jay’s David Brotherton, a sociologist specializing in youth gang culture and deportees. He spoke of a “massive explosion of the deportee population since 1996 immigration acts, under the radar screen of media, politicians, and social scientists.” He said it “has led to untold tragedies for families and communities related to the Caribbean and Latin America.”

The Department of Homeland Security maintains it is enforcing laws and rules to protect America, as mandated by Congress.

A spokesman for the Immigration and Customs Enforcement Bureau, Mark Thorn, said, “The removal of criminal aliens has always been a priority of ICE and was with our legacy agency.” The bureau is the agency of the Department of Homeland Security that replaced the Immigration and Naturalization Service’s enforcement arm.

While he maintained that the policy did not change because of the September 11 terrorist attacks, Mr. Thorn said: “Certainly, in a post-9/11 environment, ensuring the welfare and security of our communities has only become more heightened.”

Still, Mr. Mateo, speaking for many, said he is convinced the policy is causing more harm than benefits to the community.

“What makes the community safer is getting rid of dangerous criminals,” Mr. Mateo said. “What isn’t making the community safer is getting rid of those who aren’t committing crimes, but who committed crimes many years ago. Their children live here and they haven’t committed a crime since. That’s where deportation has been hurting us, not only as a community but as a country.”