BOSTON -- Frustrated lawmakers will consider subpoenas and other options to compel testimony from Baker administration witnesses who ignored requests to participate Monday in a legislative oversight hearing about failures at the Registry of Motor Vehicles.

About an hour after the Joint Committee on Transportation decided to recess its hearing until witnesses can be required to shed light on the RMV's failure to process crucial violation notices, House Speaker Robert DeLeo said he was "extremely disappointed by the lack of cooperation" from Department of Transportation officials.

DeLeo pushed back on the administration's reasoning that an investigation ordered by the administration must wrap up before the legislative committee's probe, pledging that "the Legislature's oversight role should not — and will not — be subjugated to that of an outside auditing firm."

"I am deeply troubled by the unacceptable, systemic failures at the RMV that have resulted in the need for today's actions," DeLeo said. "I call upon the Administration and MassDOT to participate in the Committee's fact-finding process without exception or qualification. The Legislature will not be thwarted in the discharge of its oversight responsibilities. The citizens of the Commonwealth deserve nothing less."

Only three of seven individuals the committee sought to answer questions — Transportation Secretary Stephanie Pollack, Acting Registrar of Motor Vehicles Jamey Tesler, and a representative from audit firm Grant Thornton — showed up at Monday's hearing.

Those who did said that, while they would attempt to answer questions, they were limited in what they could discuss because of the investigation that the firm Grant Thornton launched this month at the administration's request.

SHNS Video: Straus, Boncore after RMV hearing

Frustrated that the lack of participation "hamstrings the committee's ability to do a proper investigation," Rep. Paul Tucker suggested lawmakers recess the hearing until a time when they could guarantee witnesses would participate. The committee agreed to his motion.

"Until we get the kind of cooperation — which includes what everyone knows are the key players — why should we piecemeal what is such an important topic?" Rep. William Straus, one of the committee's co-chairs, told reporters after the hearing.

Straus and fellow co-chair Sen. Joseph Boncore, said they would meet with legislative leadership and weigh a range of methods to compel testimony. They did not rule out asking another committee with the power to do so to issue subpoenas because, as Boncore put it, "there is some intervention necessary."

"We have a duty to the public at large of the commonwealth and the families of the victims that suffered this awful loss in June to get to the bottom of these questions," Boncore said. "The Legislature's a co-equal branch of government. We have just the same responsibility to conduct an investigation into these matters, and we expect to do so."

The chairs wrote last week to the administration's transportation officials requesting a range of documents, including internal communications about record-keeping software, and testimony as it digs into how the RMV consistently failed to process out-of-state driver violation notices and failed to warn other states about suspensions in Massachusetts.

Among the witnesses sought were Erin Deveney, the former registrar who resigned days after a West Springfield man whose commercial license the RMV should have suspended allegedly killed seven motorcyclists in a New Hampshire crash, as well as the RMV's Driver Control Unit Director Keith Constantino and Merit Rating Board Director Thoams Bowes, who the committee believes work in roles closely related to the issues.

But those three did not attend Monday's hearing, and Fast Enterprises LLC, the company contracted to create the RMV's $50 million ATLAS records software, declined to participate.

Referring to the RMV employees the committee asked to testify, Pollack said in a letter to the committee last week that the Department of Transportation "would not direct or prohibit any party from attending."

Straus said he believes administration officials did not discuss the committee's request with the two RMV employees, leaving it up to the individuals themselves whether they would participate.

"I've been here 25 years and I've never seen anything like that," he said.

In addition, Pollack told chairs in her letter and at Monday's hearing that participating witnesses would have to limit their remarks. She and Tesler could not discuss in depth conditions at the registry before the late June crash that sparked the controversy, Pollack said, because of a "forensic audit" the administration hired Grant Thornton to complete within 60 days.

"We are trying to avoid any inquiries today that might undermine the accuracy of Grant Thornton's ability to develop a complete and detailed timeline and assessment," Pollack said. "We are concerned the integrity of that investigation might be cast in doubt if statements were made at today's hearing that improperly influence memories and later testimony of others who Grant Thornton will be interviewing."

Pollack told reporters after the hearing that the department will "continue to work with the committee to find a path forward that satisfies their needs but maintains the integrity of the Grant Thornton forensic audit" and reiterated ongoing efforts to improve records management. She did not take additional questions before leaving.

Neither Pollack nor Tesler gave their prepared remarks at Monday's hearing, which saw only about 35 minutes of introduction and lawmakers airing frustrations with the process before the vote to recess.

A Department of Transportation spokesman later provided Pollack and Tesler's testimony, both of which contained little new information from the interim status reports officials have been issuing in recent weeks as an internal RMV investigation continues.

"Secretary Pollack and Acting Registrar Tesler have been transparent and cooperative with the Transportation Committee’s requests since this hearing was scheduled and came prepared to deliver testimony, provided hundreds of pages of requested documents and informed the committee that some information is not yet available due to Grant Thornton’s ongoing, independent forensic review," MassDOT spokesman Patrick Marvin said in a statement. "The Secretary is committed to providing the results of this review to the Committee as soon as it is completed and looks forward to working with the Legislature to improve processes at the RMV."

At least one member of the committee expressed disappointment with the decision to recess. Sen. Dean Tran wrote on Twitter that he believed the committee should have remained in session and questioned Pollack and Tesler.

In the wake of the June crash, more than 1,600 drivers had licenses suspended based on out-of-state warnings that had piled up since at least March 2018. Gov. Charlie Baker filed legislation Friday to strengthen restrictions on who can acquire a commercial driver's license.