Faculty and Staff

Michael Alfers '97
Assistant Director of Middle School

Course(s):  Texas History-7th Grade


Mr. Alfers has been a teacher for 19 years. Throughout his teaching career,  he has taught every Social Studies class offered in the Social Studies Department.

Education: Bishop Dunne Catholic School (1997), BA University of Dallas, Currently attending the Remick Leadership Program at University of Notre Dame earning a Master Degree in Educational Leadership.

Other information about Mr. Alfers: "I have a wife, daughter, and two sons. I love to eat Mexican food. I love basketball, especially the Dallas Mavericks."


Isabel Arista

Director of Facilities



Ms. Arista has been an employee of Bishop Dunne since September 1999. She was a volunteer for three years prior to her employment.


Tom Avery

Course(s):  AP Biology, Honors Biology, Biology, Honors Life Science @ Life Science



Mr. Avery has been a teacher for 19 years. He has previously taught Science Research, Science Fair, Physical Science, Physical Education and coached football and swimming.

Education: BS in Biology and Physical Education, East Texas State University, 15 hours towards his Master of Science and Science Education.

Other information about Mr. Avery: "I was born and raised in Dallas and attended catholic schools K-12. I enjoy spending time with my wife and two daughters, music from the 60s, 70s and 80s, movies, long walks with my wife, fishing, Dallas Cowboys, gardening, Koi pounding and projects around the house."


Brad Baker

Course(s): AP Human Geography, Honors Geography, College Prep Geography, Geographic Information Systems and GIS Interns



Mr. Baker has been a teacher for 30 years.

Education: University of North Texas, Bachelor of Science-Social Studies Certificate


Sandy Brooks

Accounts Manager, Business Office



Mrs. Brooks is working towards a Business Degree. Outside school, she enjoys wedding and event planning, gardening and is an essential oils enthusiast. 


Mark C. Clifford


Course(s): AP US History, AP Government, Dual- Credit US History

214 339 6561


Mr. Clifford has been teaching for 15 years.

Education: University of Texas at El Paso, degrees in both History and Political Science. Master of History from American Public University.

Mr. Clifford routinely attends College Board AP Summer Institute. 


Julie A. Coxe

Course(s): Middle School Literature and English

214 339 6561


Mrs. Coxe has been teaching for 25 years. She has a BA in Politics from Randolph-Macon Women's College.


Sandra Dennie

Administrative Assistant

469 291 1766 



Iryna Dovzhanska

Courses: 8th grade English, Russian

214 339 6561


Mrs. Dovzhanska has both an undergraduate and graduate degree from Pedagogical University of Ukraine. She holds a Master of Arts in English.


Leslie Folz

Director of Learning Services

469 291 1778


Mrs. Folz has been teaching for 27 years. She obtained a BS in Special Education/Elementary Education from Indiana State University/University of North Texas. She received a Certification in Special Education from Notre Dame and a Master of Special Education from Dallas Baptist University.


Anna Lee Friesen


Director of Human Resources and Safe Environment

469 578 6218


Mrs. Friesen has a BS Human Relations and Business from Amberton University.


Sr. Carol George, ssnd    

214 339 6561


Course(s): Math Lab Instructor

Sr. Carol has been teaching for 51 years. She has a BA in American Studies from Notre Dame College and an MA in Education from St. Louis University.

Her summer activities include various voluntary roles including working with students in Appalachia in Kentucky; volunteering in Honduras helping out in various ministries; teaching summer Bible school sessions in New Mexico and in San Antonio; helping out with various ministries that serve the homeless in Baltimore, MD;  working with the Special Olympics in San Antonio and in Dallas. Sr. Carol says, "I found working at Providence House, a home for children  diagnosed as HIV positive, to be especially life-giving. Each of these experiences have made a life-changing impact on me and on how I strive to live life each and every day."


Melanie McGarrahan Gibson


214-339-6561, ext. 4067


Mrs. Gibson is Bishop Dunne's librarian with 10 years of teaching experience including writing to college freshmen.

She holds a BA Foreign Service from Baylor University, an MA English from Southern Methodist University and an MS Library and Information Sciences from University of North Texas 

She has volunteered with the American Library Association's Young Adult Intellectual Freedom committee and with the Texas Library Association's Young Adult Round Table. Mrs. Gibson is interested in protecting the rights of all persons to have free access to libraries, library materials and information in general.


Karen Gilley

214 339 6561


Course(s) 6th grade Earth Science, 8th grade Physical Science

Karen Gilley has been teaching for three years. She has a BA in Science from Austin College as well as a degree in Physical Therapy from UT Southwestern Allied Health in Dallas. Previously, she worked at Zale Lipshy University Hospital in Dallas, one of the world’s premier neurological diagnostic and treatment centers.  She stepped down from her position as a therapist to pursue teaching middle school science. Since commencing her teaching career she says, "I have been blessed to teach 5th grade Science, 5th grade History, 6th grade Earth Science, 7th grade Life Science and 8th grade Physical Science."


Miranda G. Gilliam

Course(s) AP Language and Composition, English III College Prep, and Honors Sophomore English

469 291 1839


Miranda Gilliam has been teaching for 21 years. She has a BA in Sociology an a MA in Literary Studies with an emphasis in Literary Studies from University of Texas at Dallas.  She taught previously at RISD where she originated the AP Capstone Seminar.

Outside of school, you'll find her, "Always training for a 10K, 1/2 marathon, or a marathon."


Mary Gracheck
Asst. Director of Advancement

469 291 1785


Mrs. Gracheck has been with Bishop Dunne for 24 years, five as a teacher and 19 as an Advancement Director. She is a graduate of University of Notre Dame and holds a BBA.


Stephen Guerrero
Assistant Principal

Course(s) Health

214 339 6561


Mr. Guerrero has been teaching for 29 years. He has a BS in Physical Education from University of North Texas, MS from East Texas State University, MA in Educational Leadership from University of Notre Dame. 

Outside of Bishop Dunne, Mr. Guerrero enjoy running and playing sports with his family. 


Paula Harrelson
Receptionist/ Administrative Asst.

214 339 6561



Daniel Ryan Harrelson

Course(s) Beginning, Intermediate, Advanced, Honors, Marching, and Jazz bands

214 339 6561


Mr. Harrelson has been teaching for 12 years. His classes have included music appreciation, music theory, choir, and math and reading remediation classes. He has degrees in Music Education and Music Performance from Arkansas State University.


Alma Keglovits

Course(s) Biology, Anatomy and Physiology, and Animals and Humans

469 291 1803


Mrs. Keglovits has been teaching for 15 years. She has taught Biology AP, Environmental Science, Earth Science, Life Science, Physical Science, and Forensics. She holds a BS in Biology from University of Texas at Arlington. 

Mrs. Keglovits received her training in education at The University of Dallas.  She is an enthusiastic Science Department Chair and teacher who has also been a club moderator and coach throughout the years.  She is a Bishop Dunne alumna who attended Catholic school in the Dallas Diocese for grades K-8 as well.  

Mrs. Keglovits likes to enhance the student experience through community service, real world application, guest speakers, lab experiments, and field trips.  Community service has included events at the Dallas Zoo, SPCA, Earth Day Texas, Bishop Arts District, Paul Quinn College, Trinity River Audubon, Cedar Ridge Preserve, Duck Team 6, Dallas Agility and Working Group, Big Fix for Big D/Spay and Neuter Network, local schools, and other events on campus.  During her professional career Mrs. Keglovits has served on school boards, and been recognized for her involvement in the care for animals in Dallas.  She has also been featured in the Texas Catholic highlighting her passion for teaching Science.  In addition to her regular teaching roles, Mrs. Keglovits has enjoyed her past positions as a mentor teacher, online education teacher, presenter at Momentous Institute and Geo Tech conferences, and instructor of Science and Math camps.


Damian McDonald

Course(s) AP English Literature, English IV, & English II

469 291 1851


Mr. McDonald has been teaching for eight years. He has also taught Read 180 (a reading intervention class), English I, Honors English I, English III, Film Studies, African-American Literature, AVID 9 (Advancement Via Individual Determination, is a nonprofit college-readiness program designed to help students develop the skills they need to be successful in college). 

Mr. McDonald has degrees in English Education and English Literature from Southeast Missouri State University and is working towards a graduate degree in School Counseling from Lindenwood University / University of Missouri. 


Hannah McKee

Course(s) 7th Grade Art, Intro to Art, Ceramics I, Ceramics II, Photo I, Photo II, Film I, Film II, Yearbook.

469 291 1858


Mrs. McKee has been teaching for four years. Previously, she worked for SFA Video Athletics in association with ESPN3. She has a BFA from Stephen F. Austin State University. 


Devin Nguyen


Manager of Donor Relations

469 291 1796


Mr. Nguyen has been with Bishop Dunne for five years. He has a BA in English Literature from University of Texas at Arlington and is working towards his Master's in Nonprofit Administration from University of Notre Dame.


Aurora Owens
Administrative Assistant to the Dean of Students Attendance Office

469 291 1770



Kathryn Perry
Director of External Relations

469 291 1786


Ms. Perry is responsible for Marketing and Communications, Admission and Advancement for Bishop Dunne.

Her previous experience includes roles at British Telecom, BNSF Railway, AIS Consulting and Source, Inc. 

Outside of Bishop Dunne, she enjoys fitness and health, working with special needs persons, photography, family and friends.

She has a BA in Communications and Journalism from Southern Methodist University.



Sandra Polewski

214 339 6561


Course(s) Chemistry

Ms. Polewski has been teaching for 21 years. Classes she has taught include Music, Musical Theatre, Biology and Algebra II. She has a BS in Biochemistry from University of Wisconsin. Outside the classroom, Ms. Polewski is both a pianist and organist and enjoys gardening, reading history and science.

Sandra Rodriguez

214 339 6561


Course(s) Orchestra Director/Strings

Ms. Rodriguez has 24 years of teaching experience that includes Orchestra Director, Choir Director, Strings and Voice Teacher and Site Leader for El Sistema at Conservatory of Music of Puerto Rico and The Dallas Symphony Orchestra. She has been a Suzuki violin Teacher for Fort Worth Youth Orchestra Program and Conservatory of Music of Puerto Rico. Ms. Rodriguez is a graduate of Conservatory of Music of Puerto Rico and holds a BA Strings and Voice.


Vladimir Sosa

469 291 1869


Course(s) Physics, Physics AP 1 and 2, CAD, Robotics, Advanced Robotics, Engineering

Mr. Sosa has been teaching for eight years. He has a BS Mechanical Engineering and a Master's Engineering, Mechanical Engineering from University of Texas at Arlington. 


Dr. Diana Torres-Rivera
World Languages Department Chair

Course(s): Spanish III, Spanish III Honors and AP Spanish Literature and Culture, AP Spanish Literature and Culture.

214 339 6561


Dr. Torres-Rivera has been teaching for 11 years. She has taught Hispanic American Literature courses in Universities in Spain and Puerto Rico, as well as Spanish classes at the Laboratory School of the University of Puerto Rico.  She has done research at the University of Oxford and presented papers and publications on peer-reviewed journals. Dr. Torres-Rivera has a BS in Hispanic Studies from University of Puerto Rico, and a Interdisciplinary Master in Spanish American Literature and History and her Interdisciplinary Doctorate in Spanish American Literature and History from University of Seville, Spain. Dr. Torres also holds a Texas teachers certificate in Languages other than English and ESL. She has been the Latinos Unidos sponsor for three years. 


Christine L. Voigt
Director of Curriculum and Instructional Technology

469 291 1773


Mrs. Voigt has 27 years of teaching experience in course that include English, Literature, Life Sciences, Social Studies, GIS and Computer Science. She holds a BS in English Language and Literature from Texas Tech University, an MS in Computer Education and Cognitive Systems from University of North Texas and a Masters of Education in Educational Leadership and Policy from Southern Methodist University. 

Mrs. Voigt is a secondary educator and award-winning author from Dallas, Texas. Her background is in English, geography, and life sciences and her specialty is infusing technology across the curriculum. In addition to her work at Bishop Dunne she is a member of the Texas Computer Education Association and has served as a past officer in special interest groups. She has been recognized at the state and national levels for her contribution to geographic education and has received multiple honors for the books Mapping Our World: GIS in Education and the Our World book series.


E. Lynn Wyman

Course(s): AP Calculus AB, College Prep Calculus, Algebra II, Geometry, and AP Statistics.

469 291 1808


Ms. Wyman has seven years teaching experience at the high school level and three years as a college TA. she previously taught dual-credit Calculus I and II, dual-credit College Algebra and Trigonometry, dual-credit Business Statistics, and Pre-calculus. As a college TA, she held problem sessions for Multivariable Calculus and Differential Equations in addition previously listed courses.  Ms. Wyman has a BS in Mathematics and BA in Medieval Studies with minors in European History and Classical Studies from Southern Methodist University and an MS in Applied Mathematics from University of Texas at Dallas.  Outside school, Ms. Wyman loves classical, rock, alternative, R&B, pop, and rap music;  singing in her church choir. She previously performed in hand-bell choirs and church orchestras (French horn) at church. She also loves sci-fi, post-apocalyptic, paranormal, and fantasy stories, TV series, and films and professes her obsession with historical and true-crime documentaries. She adds to her list a love of scratch cooking and counted cross-stitch to relax. Per Ms. Wyman, "In short, I am not your typical math nerd."