Major League Baseball umpire who umpired his first major league game in April 2010 and was hired full-time in January 2013. Some of the most notable games he has umpired include Jordan Zimmermann's no-hitter on the final day of the 2014 season and the 2014 National League Division Series between the Los Angeles Dodgers and St. Louis Cardinals.
He was born in the Chestnut Hill area of Philadelphia.
He was forced to leave an August 2010 game between the Pittsburgh Pirates and Houston Astros after being struck in the head by the bat of the Astros' Carlos Lee.
He married a woman named Allison, with whom he has sons named Alexander and Alan III, also known as Trey.
He and Vic Carapazza were both hired full-time as major league umpires in January 2010.