[3] Trecker taught at George Williams College from 1938 to 1941, when he accepted a position on the faculty of the University of Southern California.

He served as dean of the School of Social Work at the University of Connecticut from 1951 to 1968.

[3] UConn's campus library in Hartford, where the School of Social Work was located, was named in his honor.

His awards and distinctions included a citation from the American Association of Social Workers (1951), a certificate of recognition from the Connecticut Social Welfare Conference (1967), and a certificate of recognition for outstanding service from UConn in 1977.

He authored, coauthored, or edited 21 books, 46 academic journal articles, and 15 community research studies.