BOSTON – Massachusetts lawmakers are considering putting tighter regulations on automatic license plate readers, which a Worcester city councilor said could hinder law enforcement’s ability to investigate crimes.

“I understand that people are always going to be concerned about if it is an invasion of privacy, but we live in a society now where we need these tools to protect ourselves,” said Councilor-at-Large Kathleen M. Toomey, chairman of the standing committee on public safety. “I wouldn’t want to hinder the ability for police officers to be able to do detective work, or save a life or bring someone to justice.”

Three bills pending before in the Joint Committee on Transportation would place restrictions on how the technology is used and limit how long enforcement agencies can store the data – ranging from two weeks to 90 days.

ALPRs can be mounted on police patrol cars to scan and record license plate numbers of every car an officer passes.

ALPRs can automatically match the license number against a Registry of Motor Vehicles database and determine if the car is unregistered, or if the driver’s license has been suspended. It can also check the plate against a criminal justice information database to determine if the car has been reported stolen, or if it is connected to a missing person’s case.

Placing restrictions on how long this data is stored is essential to protecting basic privacy rights, according to the American Civil Liberties Union of Massachusetts.

Kade Crockford, director of the Technology for Liberty Program at the ACLU, said the issue is not that these scanners can obtain the information in the first place, but rather that the data is stored indefinitely in Massachusetts.

“This information is being used to create a database, whether someone is suspected of a crime or not,” Ms. Crockford said. “It raises constitutional issues and privacy issues, and there is a possibility of internal abuse … and externally, that information could be a major target for hackers.”

Wayne Sampson, executive director for the Massachusetts Chiefs of Police Association, said the readers are a valuable tool for solving criminal cases. Limiting the storage time frame could hinder some investigations, he said.

“We would certainly like to have a fairly reasonable amount of time to keep the data because we know a lot of times that people won’t become a suspect – or we won’t even know about a crime – until months later,” Mr. Sampson said.

ALPRs have been used in Massachusetts for about five years, Sampson said.

The Massachusetts Executive Office of Public Safety and Security received a $500,000 grant from the Federal Department of Transportation in 2010 for the purchase of these reader systems. As of October 2011, the office funded 43 agencies to purchase the readers, including the Massachusetts State Police and several departments in Worcester County.

David Procopio, spokesman for the Massachusetts State Police, said ALPRs have proven to be a valuable law enforcement tool.

“We utilize a small number of plate readers,” Mr. Procopio said in an email. “Generally speaking, the state police believe that ALPRs should be used with clear guidelines to govern data storage.”

Mr. Sampson noted there has been a general trend across the country to limit the amount of data that government officials have in every aspect – and this is a part of it.

In 2016, at least 19 states have either introduced or are considering bills regarding ALPRs, according to the National Council of State Legislatures.

Ms. Toomey said putting tight restrictions on these readers would hurt the positive impact that the technology could bring to the law enforcement agencies. She said it is important to strike a balance between civil liberties and public safety.