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The District 155 leadership team includes 16 school and district administrators who oversee and implement the board of education's strategic vision for the district.

Dr. Johnnie Thomas​

Dr. Johnnie Thomas joined Community High School District 155 in July 2012 as superintendent. Prior to assuming this leadership role, Thomas spent three years as associate superintendent for student services at the 13,000-student Township High School District 214 in Arlington Heights. There he helped elevate the district’s student support and achievement efforts at Buffalo Grove, Elk Grove, Hersey, Prospect, Rolling Meadows, and Wheeling high schools along with the district’s two alternative schools. Prior to this position, he served in various capacities with Valley View School District 365-U (Romeoville) and Chicago Public Schools.

Thomas is an advisory board member of the Loyola University School of Education, and a member of the Council for Exceptional Children, American Association of School Administrators, and Association for Supervision and Curriculum Development. He previously served as a board member for the Illinois Alliance of Administrators of Special Education and as vice president of the DuPage Township Youth Taskforce board.

He holds a bachelor’s degree from Southern Illinois University, a Master of Social Work from Loyola University (Chicago), and a doctorate in educational leadership from DePaul University.  

Erica Bruso
Director of Fiscal Services ​

A graduate of Crystal Lake South High School, Erica Bruso returned to the district as the manager of accounting in 2011. Bruso, a Certified Public Accountant, previously worked for the accounting firm of Eder, Casella & Company where she was employed as an audit and tax supervisor for the past six years. Specializing in financial statement and grant audits for school districts, local governments, and non-profit organizations, Bruso was the lead auditor on more than 20 school district audits. She holds a Bachelor of Science degree in accountancy and a master’s of accounting science, both from the University of Illinois at Urbana-Champaign. While at the U of I, Bruso made the Dean’s List every semester and was honored with the Lieby Hall Scholarship for achievement in business. She is one of only eleven Illinois recipients of the Excel Award for Outstanding Score on the Certified Public Accountant Examination in 2004, and is a member of Beta Gamma Sigma Business Honors Fraternity and the Illinois CPA Society.

Kimberly Dahlem
Director of Student Services

Kimberly Dahlem joined Community High School District 155 in July 2013 as director of student services. Dahlem is responsible for directing student support operations for the district’s four high schools and alternative campus. Prior to joining the District 155 leadership team, Dahlem spent three years as director of student services at Kildeer Countryside Community Consolidated District 96 in Buffalo Grove. She led efforts for special education, bilingual education, English language learning, and related services. Dahlem managed all legal, financial, and supervisory dimensions of the division. Dahlem previously served in various capacities as special education teacher, reading specialist, school counselor, guidance department chair, and district guidance chair over a fifteen-year period at William Fremd High School (Palatine) in Township High School District 211. Dahlem has enjoyed coaching various athletic teams and sponsoring a multitude of high school activities. She holds a bachelor’s degree in special education from Illinois State University, and a Master of Arts in reading, a Master of Arts in school counseling, and a Type 75 certification all earned from Roosevelt University. Dahlem completed her director of special education certificate through Aurora University in May 2013.

She is a current doctoral student candidate with Aurora University for the EdD Leadership in Educational Administration program.​

Jeff Daurer
Director of Operations

Jeff Daurer joined District 155 as director of operations after working as the associate vice president of facilities planning and operations for Northern Illinois University’s Division of Finance and Facilities. He managed seven departments and a $54 million operating budget. Prior to that position, Jeff was the director of capital building and planning at NIU. He was integral to major construction and renovation projects, including updates to Cole Hall and new residence hall construction project.

Jeff is a member of the Association of Physical Plant Administrators and the Society of College and University Planners. He holds a Bachelor of Science degree in marketing and a Masters of Science degree in industrial management from Northern Illinois University.


Jeremy Davis
Assistant Superintendent, Finance, Operations & Technology

​​Jeremy Davis serves as District 155’s assistant superintendent of finance and operations and chief school business official. Previously, he held the chief school business official position at O’Fallon Township School District No. 203 since 2009. ​Prior to this role, he served Wheeling Community Consolidated School District No. 21 as director of business. He holds a Bachelor of Arts degree from Baylor University, where he graduated Cum Laude, and a Master of Business Administration degree from Southern Illinois University-Edwardsville. He began his career in education as an auditor for the Illinois State Board of Education. He also holds a Type 75 administrative certificate and has served on the Illinois Association of School Business Officials Nominating Committee. Davis also has experience working in the private banking industry.

D​r. Randy Davis
Assistant Superintendent, Human Resources

Since July 2007, Dr. Randy Davis has been responsible for overseeing employment of the district's more than 650 employees. Prior to becoming D155's assistant superintendent of human resources, Davis spent ten years in administration as a high school principal, associate principal, and dean of students. As a teacher, Davis taught English and social studies. He also has coached both football and track at the high school level, serving as both an assistant and head coach in track and assistant in football. Davis received his bachelor's degree in communication studies from Northwestern University, his master's in educational administration from Northern Illinois University and his doctorate in educational leadership from National-Louis University. While at Northwestern, Davis was a member of the Wildcat football team.

George DiVenere
Director of Technology

George DiVenereGeorge DiVenere joined the District 155 team in April 2009 as director of technology. DiVenere has a master's degree in information technology from Northwestern University, 15 years of IT leadership experience, and vast technical knowledge and experience. His professional experience from the private sector has helped District 155 initiate best-practice solutions to modernize the district's infrastructure and enhance student learning. DiVenere was recognized with an Award of Excellence for Website communication by the Illinois Chapter of the National School Public Relations Association in 2014.

Dr. Steven Koch
Principal, Prairie Ridge High School

Dr. Steven Koch joined District 155 in 2001 as a Prairie Ridge English teacher. He served as English department chairman from 2005 until 2008, when he assumed his role as the district's director of staff development. He returned to Prairie Ridge as the school's fourth principal in July 2013. Dr. Koch received both a BA in secondary English education with a minor in rhetoric and an MA in English literature from the University of Illinois at Urbana-Champaign. He has both an Educational Specialist degree and a Type 75 certification from Northern Illinois University. Koch earned his Educational Doctorate from NIU for his work concentrating on public school officials' authority over student cyberspeech. Koch's wife, Katie, is a member of the District 155 math faculty, and together they have three children.

Neil Lesinski 
Director of Curriculum & Assessment

nlesinski.jpgNeil Lesinski began serving Community High School District 155 as director of curriculum and assessment in the summer of 2016. Lesinski oversees all curriculum and assessment matters including the development of curriculum maps and local common assessments. Previously, he served as the English department chairperson for Lakes Community High School District 117. He has also led the career technical education department and taught high school English for seven years. Neil holds a Type 75 certification from Concordia University Chicago, and a bachelor's degree in English from Western Illinois University. Neil is working on his doctoral degree in Educational Leadership from Aurora University.​

Steve Olson
Principal, Crystal Lake Central High School

Steve Olson has served as principal of Crystal Lake Central High School since 2002. Previously he served the district as CLC’s vice principal, and as vice principal, dean, athletic director, guidance counselor for Crystal Lake South. He began his career as a CLS social studies teacher. Olson is a member of the Association for Supervision and Curriculum Development, Illinois Principals’ Association, National Association of Secondary School Principals, and is the Illinois High School Association Legislative District Six Commissioner. He holds a Bachelor of Science in broadfield social studies from University of Wisconsin-LaCrosse, a master’s in guidance and counseling and an Illinois administrative endorsement from Northern Illinois University, and is pursuing a doctorate in educational administration from George Williams College of Aurora University.

​Shannon Podzimek
Director of Communications

spodzimek.jpgShannon Podzimek joined the district in May 2015 and serves as the director of communications. Previously, she served as a communications specialist for School District U-46, the second largest district in the state of Illinois, providing communication support for 56 schools. In addition, she initiated radio clubs for each high school and created promotional videos for the district. Shannon also has a background in producing television news for several top ABC and NBC affiliates.  She received her Bachelor of Science degree in broadcast journalism from the University of Kansas.

Jay Sargeant
Principal, Cary-Grove High School

Jay Sargeant joined District 155 as a mathematics teacher for Crystal Lake Central in 1990. Following time as a dean of students (CLS) and vice principal (CLC), Sargeant became Cary-Grove’s seventh principal in 2007. Sargeant holds a bachelor’s degree in mathematics from Bradley University, a master’s in curriculum and instruction from Concordia University-River Forest, and a Type 75 certification from Northern Illinois University. He is the Illinois Principals Association 2014 Kishwaukee Region Principal of the Year and a nominee for the IPA Illinois High School Principal of the Year.

Scott Shepard
Principal, Crystal Lake South High School

Scott Shepard joined District 155 in July 2013 as principal for Crystal Lake South High School. Previously, he served as principal for Marengo High School where he oversaw curricular enhancements including the addition of new Advanced Placement course offerings, implementation of a one-to-one digital learning environment, created student improvement programs, and focused on enhancing a culture of inclusion. These efforts yielded a “family” atmosphere and greatly improved academic achievement, helping Marengo High School earn a U.S. News & World Report rank as Illinois’ 61st best high school and the nation’s 1,956th. Shepard has 13 years of principal experience including eight years as a principal in Nebraska. He began his career as a math teacher. He was named the Illinois Principals Association 2013 Kishwaukee Region Principal of the Year and was a nominee for the IPA Illinois High School Principal of the Year.


Dr. Corey Tafoya
Assistant Superintendent, Educational Services

Dr. Corey Tafoya joined District 155 in 2014 after nine years as Woodstock High School principal. While at Woodstock, he led the school to highs in attendance rate, graduation rate, co-curricular activity participation rate, minority student achievement, and parent, staff, and student satisfaction levels. He developed the Cum Laude graduation program, and added 11 AP courses, Chinese, and Project Lead the Way. Prior to his time at Woodstock, he served as a Spanish teacher, attendance facilitator, and associate principal in Cedar Rapids, Iowa. Tafoya holds a doctorate in educational leadership and a Master of Arts Education degree both from University of Northern Iowa, and earned a bachelor’s degree in history and Spanish education from Wartburg College in Waverly, Iowa. He has been recognized as an Illinois Principals Association Regional Innovative Program Award Winner, a Northwest Herald “Ten Under 40” community leader, and is a graduate of the Leadership Greater McHenry County program. Tafoya is a member of the Iowa High School Soccer Coaches Association Hall of Fame and the Cedar Rapids Kennedy Athletic Hall of Fame.


Matthew Timmerman
Director, Instructional Technology and Staff Development

Matt Timmerman directs the district’s instructional technology and staff development activities. In this role, he liaises between information technology and the district’s 400-plus faculty members to implement, train, and support the integration of best-practice technology for the classroom. He is responsible for the new faculty induction program, faculty evaluations, and other staff development activities. Prior to joining the administrative team in 2011, he served the district as teacher on special assignment for the past five years, assisting the curriculum office with various endeavors including tracking student achievement data, co-facilitating the District Achievement Team, and helping refine course curriculum maps. Matt joined District 155 in 1998 as a mathematics teacher at Prairie Ridge High School. He has also served Prairie Ridge as an instructional technology leader, and has coached both boys’ and girls’ tennis and basketball.  Timmerman is a 1994 graduate of Cary-Grove High School. He holds a Master of Arts degree in curriculum and instruction from North Central College, a Type 75 certification from Northern Illinois University, and a Bachelor of Science degree in mathematics from the University of Iowa. Timmerman’s wife, Lauren, is a graduate of Crystal Lake Central. Together they have three children.




Community High School
District 155
1 South Virginia Road
Crystal Lake IL 60014
Phone: 815-455-8500