By Milton J. Valencia | Article Courtesy:  The Boston Globe

Law enforcement authorities raised concerns Tuesday that the drug testing scandal that erupted earlier this year at a laboratory run by the state Department of Public Health will continue to have fallout and that dangerous criminals will return to neighborhoods.

Boston Police Commissioner Edward F. Davis told a legislative committee Wednesday that he fears that a backlog of cases at the State Police crime lab, made worse by the scandal, will spur judges to release criminal defendants to the streets, instead of holding them, while their cases languish in the courts.

Davis said that of the 159 defendants released statewide because of the drug lab scandal so far, 110 have returned to Boston and pose public safety threats. Davis said that eight of those released have been ­arrested on new crimes. Some 600 offenders are expected to return to city streets because of the lab scandal.

The commissioner has long tied drug crimes to the city’s ­violence: Police say 20 percent of the slayings in Boston in 2010 were drug-related, includ­ing the Mattapan massacre case being tried in Suffolk Superior Court.

Davis said the arrests of drug offenders have made a dent in overall crime. “If we can’t get them on shootings, we hook them on the drug ­angle,” he said, adding that the offenders released because of the drug scandal could contribute to an increase in home ­invasions, turf wars, and other violence.

Davis testified before a legislative oversight committee investigating the consequences of one of the worst scandals involv­ing the criminal justice system in the state’s history. A former state chemist, Annie Dookhan, 35, has been ­accused of tampering with drug samples by mixing them, misstating their weight, and, in some cases, not testing them at all. She has been charged in criminal court in Boston with intimidating a witness by falsely reporting information to a judge, and officials said her misconduct was extensive.

Drug evidence in tens of thousands of cases in Eastern Massachusetts may have been tainted.

Defense lawyers have challenged convictions, as well as more recent charges against defendants that were based on the sullied evidence.

The lab where Dookhan worked was run by the Department of Public Health. State Police have since taken over drug testing in the state.

Law enforcement officials, from sheriffs to prosecutors to public defenders to state author­ities investigating the scandal itself, said the Legislature will need to consider the costs of the fallout.

But law enforcement officials also said police will deal with the direct public safety ­issues generated by offenders returning to city streets.

“I think law enforcement is at the end of this chain, as far as impact,” said James ­Machado, executive director of the Massachusetts Police Association and a sergeant from Fall River.

Machado and Davis told legislators the state must ­develop and pay for reentry programs to help defendants adjust to life outside prison so that they do not return to a life of crime.

Davis and Aaron Tavares — career development coordinator at Youth Options Limited, a city-funded community agency — said the city has a model program to reintroduce ­inmates to work and housing opportunities, but that funding is needed to help those leaving incarceration as a ­result of the drug testing scandal. Davis estimated the costs at $12.6 million.

Anthony J. Benedetti — chief counsel for the Committee for Public Counsel Services, the state’s public defender agency — said the state has ­only begun to see the fallout from the scandal.

He said that Dookhan’s alleged misconduct at the drug testing lab in ­Jamaica Plain taints more than 190,000 cases, because the lack of oversight at the facility calls into question all of the testing conducted at the lab, even if Dookhan was not direct­ly involved.

To cut costs and ensure the best interests of the criminal justice system, district attorneys should focus on the most violent offenders and dismiss other cases, Benedetti said.

“No one knows exactly how many cases this scandal will ­ultimately generate,” he said.

Get two weeks of FREE unlimited access to BostonGlobe.com. No credit card required.

Milton J. Valencia can be reached at mvalencia@globe.com.

Follow him on Twitter @miltonvalencia.

Annie Dookhan

Annie Dookhan

The rogue state drug lab chemist accused of jeopardizing tens of thousands of criminal drug cases faced court arraignments in Middlesex and Norfolk counties yesterday as the fallout from the case surfaced yet again — this time with the fresh drug arrest of a man who told cops, “I just got out on Annie Dookhan and I ain’t going back to jail!”

Annie Dookhan, 35, of Franklin, who authorities say tampered with drug evidence at the now-shuttered Hinton State Laboratory in Jamaica Plain, faces 27 indictments returned by a statewide grand jury last month. She has already been arraigned in Suffolk County, with upcoming arraignments in Essex, Bristol and Plymouth counties.

The scandal and Dookhan’s arrest last fall have resulted in about 200 defendants being released from jail, including Jonathan Vaughan, 26, who was arrested by Chelsea police Tuesday night after he was found drinking Natural Ice beer at a Bellingham Square McDonald’s.

Cops reported that Vaughan told them in a confrontation, “I just got out on Annie Dookhan and I ain’t going back to jail!”

Dookhan was the chemist who handled the evidence in Vaughan’s prior case, the Suffolk District Attorney’s Office confirmed yesterday.

Vaughan was sprung Dec. 14, midway through a 21?2-year stretch for his 2011 conviction on drug-dealing charges. He’s now facing new charges of drug dealing after police reported finding eight bags of crack cocaine in his pocket Tuesday night.

As Dookhan spent the day yesterday in two county courthouses, with dates ahead in three others, Dookhan’s attorney Nicolas Gordon told reporters yesterday that Attorney General Martha Coakley’s office offered to consolidate the cases in one venue, but he declined.

“It’s too early,” said Gordon, declining to elaborate on how trucking Dookhan from court to court might benefit his defense strategy.

Prosecutors “were willing to put this in one Superior Court for the time being, but until I see all the discovery, I’m not sure that’s the appropriate track to take here,” Gordon said.

The diminutive Dookhan, wearing a gray business suit and accompanied by her father, fled a scrum of news cameras yesterday morning after pleading not guilty in Middlesex Superior Court to three counts of obstruction of justice.