The engagement of Erika L. Detweiler to Daniel R. Hart, both of Livonia, Mich., is announced. A June 4 wedding is being planned. Karen and Douglas Duguay of Amherst and Samuel and Debra Detweiler of Cedar Creek, Texas, are the parents of the future bride, a graduate of University of Michigan and Wayne State University Law School. She is an associate with Charles J. Taunt & Associates, Birmingham, Mich. Her fiance's parents are Cheri and Charles Taunt of Bloomfield Village, Mich., and Robert and Debra Hart of Troy, Mich. He is a U of Michigan graduate and is an accounts payable and finance specialist with NSK Corp., Ann Arbor, Mich.