(CN) - Approaching the one-year anniversary of the partial release of the Senate "torture report," a human rights group told the government and its foreign allies they must prosecute those complicit with the abuse of detainees.
On Aug. 1 last year, President Barack Obama acknowledged for the first time that the United States "tortured some folks" in a statement paving the way for the release of a U.S. Senate report documenting those abuses.
The Senate Select Committee on Intelligence unveiled a heavily-redacted, 499-page summary of a much larger report on Dec. 9 last year.
The full report, totaling upwards of 6,700 pages, remains classified, and various lawsuits to disclose further details about the CIA's now-shuttered Rendition, Detention and Interrogation, or RDI, program continue to spiral through U.S. courts.
"While the program officially ended in 2009, the cover-up of these crimes appears to be ongoing," the New York-based Human Rights Watch said in a 159-page report it released on Tuesday.
The report rejects the Obama administration's posture that, on the question of torture, the United States should "look forward as opposed to looking backwards," a statement made by then-President-elect Obama in January 2009.
Since ratifying the Convention Against Torture in 1994, the United States has the legal obligation to criminally investigate such crimes.
The U.S. Justice Department has refused to investigate the architects of the CIA torture program, but it tapped Assistant U.S. Attorney John Durham to look into whether any agents broke the law by overstepping the agency's interrogation guidelines.
Durham shuttered the investigation without pressing charges on Aug. 30, 2012, insisting that the department lacked evidence to prosecute.
Human Rights Watch, however, remains unconvinced because Durham never questioned any detainees over the course of his probe.
"The apparent failure of the investigation to question current or former detainees undercuts any claims that it was thorough or credible," according to the group's report.
The report calls for Obama to probe his predecessor George W. Bush and Bush's senior officials, including Dick Cheney, ex-CIA Director George Tenet, former Attorney Generals John Ashcroft and Alberto Gonzales, former National Security Advisor Condoleezza Rice, and several others.
The voluminous study considers - and rejects - the possible legal defenses Bush, Cheney and others might invoke at a trial under U.S. and international law.
Human Rights Watch says there is a "very real danger" that Obama's successor will try to reinstate torture if his administration does not establish a penalty for it.
"Several 2016 presidential candidates have defended the 'enhanced interrogation techniques' and said or implied that they would use them again," the report states. "U.S. presidential candidate Jeb Bush, when asked whether he would contemplate using 'enhanced interrogation techniques' if he were elected, did not rule out the possibility and also said that waterboarding was not torture."
Republican frontrunner Donald Trump also told his throngs of supporters that "you bet your ass" he would bring back waterboarding, even if Senate investigators found it is cruel and ineffective.
"Even if it doesn't work, they deserve it anyway," Trump said, referring to detainees who have not been charged with a crime.
Human Rights Watch's executive director Kenneth Roth warned that the failure of the United States to act "undermines respect for the rule of law the world over."
"Government officials who went shopping for and helped to craft legal opinions justifying the unjustifiable shouldn't be able to rely on those opinions to shield themselves from liability," he said in a statement.
Laura Pitter, senior national security counsel at Human Rights Watch, told Courthouse News that the group gave its report to the Obama administration last week but the government has not yet responded to the group.
"Unless it's made clear that these actions were actually criminal, there's a real danger that they could be resurrected again," she said.
Pitter said that, for example, "rectal feedings without medical necessity is a criminal act," referring to one of the most shocking findings of the Senate report.
Ned Price, spokesman for the White House's National Security Council, said that the Obama administration supported declassification of the torture findings.
"As we have said repeatedly, the president supported the declassification of the summary, findings, and conclusions of the Senate's RDI report, with appropriate redactions for national security, in part to ensure these practices were never employed again," Price said in a statement.
The Human Rights Watch report includes recommendations to all foreign governments to prosecute torture under the international legal principle of "universal jurisdiction" and issues specific guidance of how France, Germany, Italy, Lithuania, Macedonia, Poland, Romania, Portugal, Spain and the United Kingdom can do so for their participation in the CIA rendition program.
The American Bar Association also urged Attorney General Loretta Lynch to pursue torture investigations in a June 23 letter.
Read the Top 8
Sign up for the Top 8, a roundup of the day's top stories delivered directly to your inbox Monday through Friday.