One of the most decorated track athletes in Maryland's rich history, Costello coached the Terrapin men from 1975-80 and led them to six consecutive ACC indoor championships, five consecutive ACC outdoor titles and an eighth-place finish at the national championships. In 1975, he was named the NCAA District Coach of the Year and served as the head coach of the United States National Indoor Team.
Costello, who specialized in the high jump as an athlete, is responsible for helping to coach the hurdlers and high jumpers. In his first season back with the program, Costello's student-athletes excelled during recent seasons.
Freshman Dominic Berger earned the championship in the 110-meter hurdles at the USATF Junior Nationals, with Berger earning a spot on the U.S. team for the Pan American Junior Games in Canada. Berger is a three-time All-American in the hurdles. Costello also aided some of the young high jumpers in the program, helping Toni Aluko to one of the top spots on the Terps' all-time list in the women's high jump indoors and outdoors as well as the ACC individual outdoor title in the high jump.
His tutelage with the Terrapins resulted in Berger finishing second in the nation at the NCAA Outdoor Championships in the 110-meter hurdles, as well as Berger winning individual hurdle titles at the ACC Championships both indoors and outdoors in 2007.
Following his time as Maryland's head track and field coach, Costello served as an assistant athletic director and headed the Terrapins' strength and conditioning program. He went on to serve as a strength and conditioning coach for the Washington Capitals and was honored in 1998 as the top ISAA strength and conditioning coach in the country, receiving the prestigious Stan Jones Award.
After achieving All-America honors in the high jump both indoors and outdoors in 1965 and 1966, he suffered a knee injury that threatened to end his career. However, he returned to earn All-America honors again in 1968 at the NCAA Championships.
Costello graduated from Maryland in 1968 with a degree in exercise physiology and earned his master's of sport science from the International Sport Science Association.