License plate readers, such as the ones seen here on the back of a Fairfax City police cruiser, are the subject of intense debates over privacy in Virginia. (Tom Jackman/The Washington Post)

Gov. Terry McAuliffe on Friday vetoed legislation that would have limited how long law enforcement may store data from license-plate readers and other surveillance technology, despite widespread support from lawmakers and civil liberties advocates.

In siding with police and prosecutors, McAuliffe (D) said the measures were rushed to a vote in the recent legislative session and would have added unintended burdens to fighting crime. He referred the issues to a committee composed mostly of law enforcement officers and their representatives for further study.

The decision put McAuliffe at odds with a rare coalition of privacy hawks, including tea party activists and the American Civil Liberties Union — and it left some scratching their heads about the governor’s motives.

Others said the vetoes gave McAuliffe a platform to show that he’s a moderate Democrat and friend of law enforcement, even if it puts him on the opposite side of a growing public call for protections against police power.

Terry McAuliffe, governor of Virginia, on Monday, April 27, 2015. (Patrick T. Fallon/Bloomberg)

“It would be unwise for me to sign legislation that could limit the tools available for legitimate law enforcement purposes and negatively impact public safety, or derail major transportation projects and jeopardize time-saving technologies that are essential to our economy, our citizens, tourism and the efficient conduct of business,” McAuliffe said in his veto message.

Advocates for reining in police retention of data said the bills were carefully written to capture only technology that “indiscriminately vacuums up” data. The measures, they said, would have given law enforcement leeway to keep private data when it is needed to investigate crimes.

“On this issue I think that they’re tone deaf to what the general public wants, what the law says and what constitutional principles say,” said Del. Richard L. Anderson (R-Prince William).

Anderson and Sen. J. Chapman “Chap” Petersen (D-Fairfax) each introduced legislation this year that would have required police to purge data from license-plate readers within seven days, unless they have a warrant or a pending criminal or terrorism case.

Police pointed to numerous examples of how license-plate data was used not only to check plates against a list of stolen cars and wanted persons but to solve cases using license photos in their database. In Arlington, police located a missing 67-year-old man, near death, who had not returned home but whose license had been photographed elsewhere two days earlier. And in March, Alexandria police were able to provide a photo of a car that had been carjacked in Annandale by a prisoner who had escaped from Inova Fairfax Hospital, Fairfax County police said.

McAuliffe amended the twin measures to extend the seven-day limit to 60 days, and he narrowed the focus from surveillance technology to simply “license plate readers.” The House and Senate accepted McAuliffe’s amendments that limited the legislation to only license-plate readers, but they rejected the 60-day extension.

On Friday, McAuliffe vetoed that legislation, meaning that current law, with no restrictions on data retention, stands.

Quentin Kidd, a political science professor at Christopher Newport University, said McAuliffe’s position is unsurprising for a pro-business Democrat focused on job growth.

Kidd said that although McAuliffe broke the mold of previous Virginia Democrats who have run statewide by supporting gay marriage and gun control, he has more in common when it comes to the politics of policing with his friend Bill Clinton, who famously put 100,000 police officers on the street and ran for president amid the 1992 Rodney King riots in Los Angeles.

The surveillance bills give the public an “opportunity to see this part of Terry McAuliffe and the kind of Democrat he is,” Kidd said. “I’ve never thought of McAuliffe as this flaming lefty. He’s been portrayed this way because he ran against very right-wing, libertarian Ken Cuccinelli.”

In fact, experts say, McAuliffe’s Virginia was positioned to become a national leader in restricting law enforcement use of surveillance equipment had the legislation become law. Now, they say, the commonwealth is back to square one, with a law that does not address license-plate readers, and agencies maintaining data for differing lengths of time.

However, in a victory for privacy advocates, the governor signed a separate measure that requires law enforcement to seek a warrant before using a drone in an investigation, adding Virginia to the list of only 11 states that do so, according to the ACLU.

Virginia Secretary of Public Safety Brian Moran said a 45-day session was not long enough to consider all ramifications, which he said could have prohibited state and private toll collectors from using cameras to record and process tolls on highways as well as police body cameras, which McAuliffe supports.

Petersen said the legislation had been publicly discussed and considered for more than a year, after Anderson first introduced a bill in the 2014 session. He said the measures would not have applied to devices such as traffic cameras or police body cameras. The bill says “data is of unknown relevance and is not intended for prompt evaluation and potential use.”

“This whole ‘Patriot Act’ mentality has to end,” Petersen said. “The police are not always right. We don’t live in a police state. The idea you can observe people, track people, without any suspicion, that’s a violation of the right to be left alone.”

Anderson said he suspected McAuliffe had “gone native,” with law enforcement representatives, appealing to their shared responsibility to protect the greater good.

“They have prevailed on him so heavily he’s lost sight of the overriding necessity for protecting the privacy of the citizens of Virginia,” Anderson said.

At the start of the legislation session, the McAuliffe administration wrote lawmakers a letter asking that surveillance bills be referred to a panel for further study — a suggestion they ignored. Now, Moran said, the panel will add the issues to its agenda.

Ken Cuccinelli II, the former attorney general who lost to McAuliffe in the 2013 gubernatorial race, said there’s another reason for the panel: “That’s the classic way you kill something.”

In 2013, Cuccinelli issued an opinion that data collection was not legal under existing state law without a direct link to an active case. The state police began to purge their data within 24 hours, but police departments in Northern Virginia elected to ignore his opinion and keep the data for up to two years.

“None of them have offered an alternative legal explanation for my interpretation,” he said. “They just say an attorney general opinion doesn’t bind us — but the law does.”

Cuccinelli and Claire Gastanaga of the Virginia chapter of the ACLU, two people rarely on the same side of any issue in Richmond, recently teamed — in an op-ed in the Richmond Times-Dispatch — urging McAuliffe to sign the bills.