A Dominican immigrant and suspected drug dealer who has used at least 14 aliases while in this country has been deported a whopping five times over the past decade — four of them from Massachusetts — in a case that highlights the revolving door in a lax immigration system, a Herald probe found.

Juan Laboy — who court documents say had addresses in Lawrence, Malden and Methuen — was last deported in April after his third conviction in federal court for illegal re-entry, for which he served a year in prison. Illegal re-entry is punishable by up to two years behind bars.

Among Laboy’s no fewer than 14 aliases are: Victor Aibar, Jorge Zenon Ferreira Fernandez and Victor Feliciano-Viera.

Laboy was arrested twice in Massachusetts: in Roxbury in 2010 for drug trafficking and in Lowell for drug possession and unlicensed operation in 2015. In the Roxbury bust, police say they found four bricks of heroin in a car he was in along with one of his four children.

Laboy was charged under two different names in both cases, but neither resulted in a conviction. Prosecutors dropped the Roxbury case due to lack of sufficient evidence, and the Lowell case was apparently pre-empted by Laboy’s most recent federal illegal ­re-entry case and deportation.

If he’d been convicted in either drug case, Laboy would have been subject to much longer prison terms. Illegal immigrants who re-enter the U.S. without government approval are subject to 10 years imprisonment if they are convicted of a nonaggravated felony.

Records also show that Laboy and his wife received taxpayer-financed Medicaid while in Massachusetts to pay for the treatment of their son, who suffers from epilepsy.

Laboy was among 41 undocumented immigrants that the U.S. Attorney’s Office in Boston prosecuted solely for illegal re-entry in 2013, and he was among 90 prosecuted last year.

U.S. Rep. Matt Salmon (R-Arizona), who has filed a bill to jack up the penalty for illegal re-entry to a mandatory five years, said the revolving door illustrated by Laboy’s case has “become more the norm,” and called penalties on the books “a slap on the hand.”

The Herald reported yesterday that Massachusetts deported the lowest percentage of illegal aliens of any state in the U.S. last year — and had the third highest rate of granting asylum — emblems of the Obama administration’s increasingly lax policy on immigration.

Lawyers for Laboy cited his lack of convictions on anything other than illegal re-entry charges to successfully argue for more lenient sentences, presenting him as a father who kept re-entering to support his children and had trouble finding good work in the Dominican Republic.

“The Defendant is a man adrift between two worlds, able to thrive in neither,” wrote one of Laboy’s attorneys, Murat Erkan, in a sentencing memorandum on his second illegal re-entry case, for which Laboy served 10 months in prison.

In his third illegal re-entry case, Laboy’s attorney, Joshua Hanye, made no reference to his drug arrests.

“There is nothing to support imposition of a sentence at the high end of the range, as this is a mine-run (run of the mill) illegal entry case,” Hanye wrote in a sentencing memo. “For all the reasons faced by poor people in impoverished countries, it is not uncommon for people to reenter illegally more than once.”

Erkan and Hanye did not respond to requests for comment.

Christina Sterling, spokeswoman for U.S. Attorney Carmen M. Ortiz, said the government’s sentencing recommendation in Laboy’s third case was “consistent with the applicable United States Sentencing Guidelines.”

“The Court imposed a sentence which it believed appropriate in light of Mr. Laboy’s history of entering unlawfully,” Sterling said in a statement.

“It’s become almost a non­deterrent to offenders who feel that waiting it out and beating the system is something that’s fairly easy,” Salmon said.

According to a sentencing memo, Laboy paid border “coyotes” to transport him through Mexico the first time he crossed the U.S. border in 2006; he walked through desert for two days before reaching Texas, where he was apprehended by border patrol and deported after two months.

Later, Laboy was able to regain entry through unspecified means and traveled by bus to Brockton, where a cousin lived. He met his wife, Kenia Perez, in Lawrence. Perez was arrested with Laboy in Roxbury in 2010 and also deported; court documents indicate she was also using an alias.

They were arrested after officers with the Boston police drug unit saw them enter a vehicle that had been driven in a way “consistent with that of an individual waiting for a drug delivery” about 9:30 p.m., according to a police report. The couple had one of their children with them in the backseat, police reported.

Police found four bricks of heroin and $7,400 cash in a hidden compartment under a passenger seat in the car, and arrested Laboy, who told police his name was Victor Viera, as well as Perez and the driver, Antonio Acevedo. All were charged with drug trafficking.

Prosecutors ultimately dropped charges against Laboy and his wife because the evidence was deemed “not sufficient to prove that connection beyond a reasonable doubt,” said Jake Wark, spokesman for the Suffolk District Attorney’s Office.

Acevedo, also known as Bacilio Aybar-Marta, was indicted and convicted of drug trafficking, and sentenced to five years in state prison in 2012. He was paroled in 2014 and deported.

Laboy resurfaced here twice more.

In 2013, an Immigration and Customs Enforcement agent acting on a tip from the Drug Enforcement Administration spotted Laboy while conducting surveillance at an apartment complex in Methuen.

The agent reported Laboy was paying for two apartments in the complex by money order. This led to Laboy’s second illegal re-entry arrest and conviction.

Yet he was back in February 2015, when Lowell police on drug surveillance arrested him after observing behavior consistent with drug dealing and pulled him over, finding a bag of cocaine in his jeans. Laboy was subsequently convicted on his third illegal re-entry charge. The Lowell case was never adjudicated.

Salmon said it’s been a tough sell introducing a five-year mandatory sentence for illegal re-entry.

“There is a lot of prison overcrowding with mandatory sentencing on drug offenses, and a lot of people are really sensitive about mandatory sentence,” he said. “The problem, as I think you’ve seen in this story, is that the current law is not really working.”