CLEVELAND, Ohio - A tiny fraction of license plates scanned by law enforcement cameras actually produce "hits" that lead police to criminal suspects, data collected by the American Civil Liberties Union show.

The civil rights group, which believes the cameras raise privacy concerns, reviewed tens of millions of scans from 293 police departments and five state agencies and found hit rates of between 0.01 and 0.08 percent.

"While it is legitimate to use license plate readers to identify those who are alleged to have committed crimes, the overwhelming majority of people whose movements are monitored and recorded by these machines are innocent, and there is no reason for the police to be keeping records on their movements," the ACLU wrote in a 2013 report about the data. "The vast majority of license plate data are collected from people who have done nothing wrong at all."

The ACLU is raising similar concerns in Northeast Ohio as Cuyahoga County prepares to buy 73 license-plate scanners for use at busy intersections in Cleveland and 18 suburbs. Council is expected to vote on the legislation on Dec. 12.

Law enforcement officials acknowledge that very few of the plates scanned by cameras match plates filed in federal and state criminal databases. But they said the matches are nonetheless invaluable in investigations and have helped them solve numerous cases.

Automated license-plate readers have led to arrests and the recovery of stolen vehicles, said Heather Whitton of the Cincinnati Police Department. She is the program manager for the regional system which has been using 36 plate-reading cameras at intersections since 2011.

"They have helped us solve some really big cases we may not have been able to without them," she said. She said police used license plate data to fined a van wanted in connection to a shooting that occurred outside a bar and to locate an SUV involved in a hit-skip.

The information captured from license plates is scanned against the FBI's National Crime Information Center's "Hot List." The hot list contains plate information on numerous factors including stolen vehicles, warrants attached to vehicle owners and missing persons. Local law enforcement agencies can add plates into the system for vehicles of interest.

The cameras are already in use in parts of Northeast Ohio.

Since 2010, license-plate reading cameras mounted on police vehicles have been used by 19 law enforcement agencies in Cuyahoga County and in nine cities in Ashtabula, Geauga, Lake and Lorain counties.

The 38 cameras took a total of more than four million images in the last year, said Brandy Carney, director of the county's Department of Public Safety and Justice.

Fairview Park Police Chief Erich Upperman, who has worked on the county's camera proposal, said the Chagrin Valley dispatch center stores the license-plate data, but no reports have been issued regarding how many scans have produced hits.

But Upperman said removing even one criminal off the streets is a validation of the technology.

"As far as we are concerned, it is worth it," he said.

He offered two examples of arrests made because of the cameras:

License plates scanned in the parking lot of a motel led to the arrest two hours later of a suspect in a burglary at one of the motel rooms.

A plate scanned in another parking lot indicated an arrest warrant had been issued for the owner. The car contained thousands of dollars of stolen goods.

As for the ACLU's concerns about privacy, Upperman said people's movements are monitored all the time by security and other cameras.

"We've had eight solid years of using this and there has been no hint of inappropriate use of data," he said.

The ACLU has said it is concerned about the ability to collect and share data on all drivers. Several states, but not Ohio, have set limits on license plate reader use.

The group's 2013 report, "You Are Being Tracked: How License Plate Readers Are Being Used To Record Americans' Movements," is the most recent study on the effectiveness of the technology, officials said.

Here's what the ACLU found on data hits:

Maryland: The state's data fusion center collected more than 29 million license plate records from January through May 2012. Only 0.2 percent of those license plates, or about 1 in 500, were hits. Of those, 97 percent were for a suspended or revoked registration or a violation of the state's vehicle emissions inspection program.

Minnesota: Of the 1,691,031 plates scanned between 2009-2011 by the Minnesota State Patrol, 852 citations were issued and 131 arrests were made. That is a hit rate of 0.05 percent.

Burbank, Illinois: Between August 2011 and July 2012, 706,918 plates were read with a 'hit' rate of 0.3 percent.

Rhinebeck, New York: Between January and March 2012, 99,771 plates were read with a 'hit' rate of 0.01 percent.

High Point, North Carolina: Between August 2011 and June 2012, 70,289 plates were read with a 'hit' rate of 0.08 percent.

The Bay Area Urban Areas Securities Initiative and the Northern California Regional Intelligence Center conducted a pilot project with automated license plate reading cameras at an intersection in Larkspur, California between October 2015 and April 2016.

During February, March and April, when the cameras were fully operating, about 1.1 million license plates were captured each month, according to a report issued in July 2016.

Of the total of 3,996,094 plate reads during the seven months, there were 985 matches to 'hot list' databases. Of those, 973 were lost or stolen plates. There were 4 felony wants, 3 sex offenders, and 5 on the violent gang/terrorist list.

Note: Heather Whitton's name was misspelled in an earlier version.