More than three-quarters of New Jersey police departments failed to give the public correct information when they were asked how to file a complaint against officers, the American Civil Liberties Union has found.

The organization Tuesday released a report based on a 2012 survey of 497 departments. It followed a similar study conducted in 2009 that produced similar findings. "The results remained disconcerting," the report said. "Once again, a majority of local departments provided inaccurate information in response to the most basic questions regarding individuals' rights to file [internal affairs] complaints."

Of 34 departments checked in Camden County, only Pine Hill correctly answered all five questions about filing complaints against officers.

In Burlington County, 10 of 33 departments checked provided accurate information, while in Gloucester County, four departments provided accurate information out of 24 checked.

"It absolutely is indicative of a bigger problem," said Alexander Shalom, an ACLU policy lawyer who worked on the study. "The law is pretty clear. If there is enough information to investigate, they must do an investigation."

Departments do too little with complaints to identify problems, Shalom said. As a result, citizens stop complaining.

He pointed to Camden, where years passed before a rogue narcotics unit was properly investigated for planting drugs on suspects.

In that case, four officers have been convicted; charges against 200 people have been dropped; and the city has agreed to pay $3.5 million to settle claims by 88 people improperly jailed.

"If the complaints had been investigated, it would have saved the city much of the $3.5 million," said Shalom, who represented one man who was jailed for more than a year after police planted marijuana laced with PCP on him.

The Camden County Prosecutor's Office has since worked closely with the ACLU to create training materials on handling complaints against officers, Shalom said.

The New Jersey Attorney General's Office responded to the ACLU's report Tuesday by advising police chiefs to review procedures and use training materials provided by the state.

"Proper training will greatly assist in addressing the discrepancies we are seeing," said Paul Loriquet, director of communications for the attorney general. "We will be directing all police departments in the state to make use of these new materials."

The law requires that police accept anonymous calls, third-party and juvenile complaints, and reports from undocumented residents without threatening them with deportation. In 75 percent of calls made to departments by ACLU volunteers for the study, police officials gave inaccurate information, the ACLU said.

At times, callers were told they had to make the report in person, that juveniles must have an adult present, that anonymous complaints could not be taken, and that immigration officials might be notified about undocumented residents.

With many of the police responses, Shalom said, officials were professional and tried to be helpful, but gave incorrect information.

Remenda Mears, 42, of Paulsboro, said she was not surprised by the report. Two years after she questioned the conduct of police officers who arrested her three sons, the Paulsboro department has not issued a finding on the officers' conduct.

Her sons filed a criminal complaint against the officers, alleging that they had punched and kicked them during the 2011 arrests. Among the charges filed against the sons were disorderly conduct, resisting arrest, and making terroristic threats. "My boys were not treated with respect, nor was I," said Mears, a medical technician. "The police used their law to take advantage of the whole situation."

The criminal case was settled this month when both sides agreed to drop charges.

On Tuesday, Paulsboro Police Chief Chris Wachter, who took over the department four months after the incident, said he has reopened the internal investigation into the case.

Pennsauken Police Chief John Coffey said he provided more guidance to officers after the ACLU's 2009 report. "I know for sure we have gotten a lot better," Coffey said.

He referred to one case in which a resident complained about an off-duty officer who got into a bar fight. The resident did not want to sign a criminal complaint against the officer in 2011.

"We still have to investigate" internally, Coffey said.

This week, the officer was suspended without pay for six months, the chief said. "We went out of our way to make sure complaints were filed."

Ken Aita, the lawyer who represents the person who reported the bar fight, said having a department investigate itself can be problematic.

"They try to dissuade you from filing complaints," Aita said. "I learned this through my clients."