It's been six months since the Senate Intelligence Committee released its damning investigation into CIA torture, and still, no perpetrator has yet to be charged with a crime.

On Tuesday, a coalition of leading human rights groups and more than 110,000 people sent a letter calling on U.S. Attorney General Loretta Lynch to launch a truly independent investigation to ensure that there is a measure of justice and accountability for the "horrific" acts done at the hands of the U.S. government.

The letter argues that the previous investigation into the CIA's use of waterboarding, launched in 2009 by Assistant U.S. Attorney John Durham, was insufficient on many counts and has failed to bring about any conviction.

Now, in light of the "significant new information" presented in the Senate Select Committee on Intelligence Committee (SSCI) report, the letter calls on Lynch "to appoint a career prosecutor as a special prosecutor to review it, along with the files from the Durham investigation, to ensure that there is a comprehensive criminal investigation into the conduct documented by the Senate torture report, as well as the authorization for that conduct."