"The USA denies responsibility for the CIA?"

Sounds like a question a prosecutor would ask a witness, followed by "Please answer yes or no!"

Look... in any police or security agency, the problem is to recruit and hire officers/agents/directors...etc. who are competent to do the job, but who are willing to follow the (sometimes ambiguous) rules and submit to control & review from above.
    The very system that gives them freedom to search, detain, question and imprison possible criminals also tempts some of them to stretch the rules and apply their own standards to the situation. In fact, because they spend enormous amounts of time dealing with acknowledged 'dangerous elements' can alter and distort their motives for being in the profession.... and let's face it... some join these organizations, from basic police to the most secret govt. agencies, BECAUSE they have a personal agenda.

   So, the question about whether the USA "denies responsibility" is an equivocation based on de facto using two concepts of "responsibility" in the same question. 1)Did we hire & train those guys and send them out to do a job? and 2)can we efficiently monitor & control the details of what they do!?
In the simple case of a policeman, we currently have the situation in Missouri, where it looks like a seemingly trusted and average policeman went way over the line and executed a young man in a highly dubious manner. Who is "responsible"? Maybe that officer will be punished for flawed behavior... maybe not. Now, suppose they fire the police chief and everyone who trained him.... is the city/state still "responsible" for what he did? The real answer is yes AND not. The state may have to pay damages, but the new police chief and the governor of the state are not "responsible" for the guy's shooting.
   In the case of the CIA and the US congress, it is many times more complex, partly due to the importance of the issues, partly due to the overlapping "responsibilities" of Congress, the president, the director of the CIA,and the various levels of agents who carry out actions. The need for security & secrecy in certain areas means that it is often the case that those who are ultimately "in charge" may have little of no idea what is happening at the agent level until things have gotten out of hand.
And yet... you want to make sweeping statements about 'the USA denying responsibility!' for something that happened 10 years ago, with a different set of managers.
What they are "responsible" for is changing the system and trying VERY hard to root out the problem agents and to provide some sort of oversight & openness in an agency which, by its very nature, is required to be secretive & closed to most scrutiny. (Now.. throw in the NSA and the FBI and a few others, and write, in your copious spare time, using *the wonderful, intelligent, help of the dedicated members of Congressional committees*, *choke*... a few laws & rules designed to avoid embarrassing headlines in the future. Do this while the media & amateur pundits write scathing headlines about "denying responsibility"

Oh, it IS easy to point at problems... and almost as easy to just paint an entire country as failed and flawed because of the errors of a few.

Lots of work, hmmmm?