Only 1 percent of police brutality complaints are substantiated by internal affairs investigations in Central New Jersey — an anomalous statistic revealing that either New Jersey cops are uniquely well behaved, or investigators routinely deny justice to citizens and instead cover up police abuses.

The troubling report comes from the Courier News and Home News Tribune, which found that only 1 percent of brutality accusations made against Central New Jersey police agencies are ever corroborated by subsequent investigations. Nationwide, about 8 percent of brutality complaints are deemed truthful, according to AllGov.com.

Why the discrepancy? Are mid-Jersey cops uncommonly scrupulous public servants, constantly subjected to false and malicious reports of abuse?

Or are Garden State internal affairs departments especially deceitful?

Civil liberties experts fear the latter explanation is more likely.

“Police in general are incapable of investigating their own officers,” said Richard Rivera, a former cop and current leader of the Civil Rights Protection Project. “They do not adequately analyze complaints or use of force incidents. They are woefully under-trained in investigating complaints related to excessive force.” (RELATED: Parents call police for help, cops show up and kill their 18-year-old son)

Alexander Shalom, a staff attorney for the American Civil Liberties Union of New Jersey, said the numbers should be taken seriously.

“This either means you have departments that are exceptionally well behaved or it means departments are not doing a sufficient job of investigating themselves,” said Shalom in a statement.

South Brunswick Police Chief Raymond Hayducka disagreed with this assessment.

“Agencies do a good job of self-policing,” said Hayducka, a former president of the New Jersey State Association of Police Chiefs, in a statement.

But some Central New Jersey municipalities had a complaint affirmation rate of zero. The cities of Elizabeth, Woodbridge, New Brunswick, Perth Amboy and Linden accrued a grand total of 400 police brutality accusations over the last five-years, but not a single one was sustained by internal affairs. (RELATED: Lawsuit: Omaha police beat man on street, threw woman out of wheelchair)

New Brunswick investigator Richard Rowe was convicted of mishandling 81 internal affairs investigations and sentenced to two years probation. One officer investigated by Rowe’s agency, Brad Berdel, was cleared eight times.

In response, some political leaders have suggested giving investigative powers to different agencies, such as state investigators or grand juries involving citizens.

Hayducka expressed opposition to these solutions, implying that the job of internal affairs was to demonstrate that officers “clearly were in the right.”

(RELATED: Finally going to jail: Cops who beat inmate, lied about it, destroyed video evidence)

Follow Robby on Twitter