The NCAA on Friday said it “could not conclude” whether the University of North Carolina violated NCAA rules over a series of academically deficient “paper courses” taken by a sizable number of student athletes over the course of nearly two decades. The school’s athletic programs will not face sanction after an NCAA investigation that lasted nearly 3 1/2 years. In a statement, the NCAA said it agreed with North Carolina’s assertion that the governing body lacked jurisdiction to rule on such academic matters. “While student-athletes likely benefited from the so-called ‘paper courses’ offered by North Carolina, the information available in the record did not establish that the courses were solely created, offered and maintained as an orchestrated effort to benefit student-athletes,” Greg Sankey, the panel’s chief hearing officer and commissioner of the Southeastern Conference, said in the statement. “The panel is troubled by the university’s shifting positions about whether academic fraud occurred on its campus and the credibility of the Cadwalader report, which it distanced itself from after initially supporting the findings. However, NCAA policy is clear. The NCAA defers to its member schools to determine whether academic fraud occurred and, ultimately, the panel is bound to making decisions within the rules set by the membership.” The saga dates from 2011, when the News & Observer published the first in what became a series of stories that ultimately uncovered one of the worst academic fraud scandals in the history of American higher education. From 1993 until 2011, a university-commissioned investigation later found, two employees in North Carolina’s African and Afro-American studies department offered no-show “paper classes” — courses that required no attendance, only that students submit one paper, which often earned an A or B regardless of quality — to thousands of students, many of them athletes. (The report was spearheaded by Kenneth L. Wainstein, a partner with the Cadwalader, Wickersham & Taft law firm.) The NCAA found only two violations, both of them committed by the two academic employees over their failure to cooperate with NCAA investigators. Only one of them — former African and Afro-American studies department chair Julius Nyang’Oro — faces any sort of sanction, and he retired in 2012. The North Carolina employees — one of whom was indicted on a felony fraud charge connected to these “paper classes” that was later dropped — were motivated to help students, especially athletes, keep their grades up, the university report found. Nearly half of the thousands of students who took the classes over the years were athletes. The two sports most represented among these phony classes: football and men’s basketball. Former star football player Julius Peppers took several of the courses, and Rashad McCants — a star from the Tar Heels’ 2005 NCAA men’s basketball championship team — has said he took several bogus classes, and that tutors directed him to the courses and wrote papers for him. This was all well known in the athletic department, McCants has claimed. Coach Roy Williams and other players from the 2005 team have disputed McCants’s allegations.