Question: What was the main topic of the United States Congressional hearing where Brian McNamee appeared to speak about this retired American baseball pitcher nicknamed "Rocket?"

Context paragraphs:
United States case law topical index: On finding the simple categorization of United States Supreme Court articles on Wikipedia insufficient for purposes of easily searching for case law that deals with a certain topic, this index is being created to make things easier.  Topics are listed alphabetically.  If a topic has a sub-topic, the subtopic is listed under the main topic.  (i.e. Establishment Clause is listed under F as a sub-topic of First Amendment, rather than E)

Brian McNamee: Brian Gerard McNamee (born c. 1967) is a former New York City police officer, personal trainer, and strength and conditioning coach in Major League Baseball who is most notable for testifying against former New York Yankees pitcher Roger Clemens at a 2008 United States Congressional hearing that concerned the veracity of the 2007 George J. Mitchell Report.

Mike McCormick (pitcher): Michael Francis McCormick (born September 29, 1938) is a retired American baseball pitcher who played 16 seasons in Major League Baseball (MLB).  He played for the New York and San Francisco Giants, Baltimore Orioles, Washington Senators, New York Yankees and Kansas City Royals from 1956 to 1971.  He batted and threw left-handed and served primarily as a starting pitcher.

William Bulger: William Michael "Billy" Bulger (born February 2, 1934) is a retired American Democratic politician, lawyer, and educator from South Boston, Massachusetts, whose eighteen-year tenure as President of the Massachusetts Senate is the longest in history, and who was also president of the University of Massachusetts.  He was forced to resign from the latter post after he refused to testify in a 2003 Congressional hearing about communications he had with his then-fugitive brother, James "Whitey" Bulger, Jr., a Boston crime boss.

Congressional Hearing Health Caucus: The Congressional Hearing Health Caucus (Caucus), a caucus of the United States Congress, was created in 2001 in cooperation with the National Campaign for Hearing Health, a public education and advocacy project run by the Deafness Research Foundation (now called the Hearing Health Foundation.)  The focus of the Congressional Hearing Health Caucus includes several aims that promote hearing health and encourage universal newborn hearing health screenings for all Americans.  Those most at risk for hearing-related concerns are newborns, infants, and the elderly, particularly if such issues are left undetected.  Therefore, a primary goal of the Congressional Hearing Health Caucus is to see that auditory abilities of all Americans are screened, including universal hearing screening for newborns.  One of the co-founders and co-chairmen of the Caucus was former Congress Member James T. Walsh (R-NY).  The Director of the National Campaign for Hearing Health at the time of launch of the CHHC, was Elizabeth Thorp, who had herself been born with unilateral deafness not discovered until she was eight years old.

We the People: The Citizen and the Constitution: We the People: The Citizen and the Constitution National Finals, sponsored by the Center for Civic Education, is a yearly competition involving high school students from throughout the United States.  The national finals simulates a congressional hearing and is held at the National Conference Center in Leesburg, Virginia, and in congressional hearing rooms on Capitol Hill.  Each class is divided into six units, each composed of three to six students.  Each unit focuses on a particular area of Constitutional interest - from the philosophical underpinnings and Constitutional Convention to the Bill of Rights and modern day implications.  Students are judged on criteria such as their understanding, reasoning, responsiveness, and use of constitutional applications.

Ed Wells (baseball): Edwin Lee Wells (June 7, 1900 – May 1, 1986), nicknamed "Satchelfoot", was an American baseball pitcher.  He played professional baseball for 14 seasons from 1923 to 1936, including 11 seasons in Major League Baseball for the Detroit Tigers (1923–1927), New York Yankees (1929–1932), and St. Louis Browns (1933–1934).  Wells was a left-handed pitcher, with a hard fastball and a slow curve.  Wells appeared in 291 major league games with a 68–69 record and won a World Series championship with the Yankees in 1932.

Bob Gibson: Robert Gibson (born November 9, 1935) is a retired American baseball pitcher who played 17 seasons in Major League Baseball (MLB) for the St. Louis Cardinals (1959–75).  Nicknamed "Gibby" and "Hoot", Gibson tallied 251 wins, 3,117 strikeouts, and a 2.91 earned run average (ERA) during his career.  A nine-time All-Star and two-time World Series champion, he won two Cy Young Awards and the 1968 National League (NL) Most Valuable Player (MVP) Award.  In 1981, he was elected to the Baseball Hall of Fame in his first year of eligibility.  The Cardinals retired his uniform number 45 in September 1975 and inducted him into the team Hall of Fame in 2014.

John Donaldson (pitcher): John Wesley Donaldson (February 20, 1891 – April 14, 1970) was an American baseball pitcher in Pre-Negro league and Negro league baseball.  In a career that spanned over 30 years, he played for many different Negro league and semi-professional teams, including the All Nations team and the Kansas City Monarchs.  Researchers so far have discovered 667 games in which Donaldson is known to have pitched.  Out of those games, Donaldson had at least 400 wins and 5,002 strikeouts as a baseball pitcher.  According to some sources, he was the greatest pitcher of his era.

Roger Clemens: William Roger Clemens (born August 4, 1962), nicknamed "Rocket", is a retired American baseball pitcher who played 24 seasons in Major League Baseball (MLB) for four teams.  Clemens was one of the most dominant pitchers in major league history, tallying 354 wins, a 3.12 earned run average (ERA), and 4,672 strikeouts, the third-most all time.  An 11-time All-Star and two-time World Series champion, he won seven Cy Young Awards during his career, more than any other pitcher in history.  Clemens was known for his fierce competitive nature and hard-throwing pitching style, which he used to intimidate batters.

Supporting paragraphs: Brian McNamee Roger Clemens
Answer: George J. Mitchell Report