DEDHAM – Katherine C. Lawson is pleased to announce the engagement of Casey A. Lawson to M. Elizabeth Prenger, both of Boston. Elizabeth is the daughter of Michael and Pamela Prenger of Baltimore and Casey is the son of Katherine C. Lawson of Dedham and the late Charles W. Lawson Jr. Elizabeth is a 2001 graduate of St. Paul’s School for Girls in Brooklandville, Md., and a 2005 graduate of Wheaton College in Norton, Mass. She is a project assistant for Susan Reddick Design of Cambridge, Mass. Casey is a 2000 graduate of John Bapst Memorial High School in Bangor, a 2001 graduate of Kimball Union Academy in Meriden, N.H., and a 2006 graduate of Wheaton College. He is a teacher of history and political science at Phoenix Charter Academy in Chelsea, Mass. Casey and Lizzie met while attending Wheaton College. They are planning a Nov. 28, 2009, wedding in Baltimore.