The city's school district has announced new top administrators at several elementary and middle schools:
* Pete Schaefer, principal of Helen Estock Elementary, who joined the district in 1967, has been named principal of Barbara Benson Elementary. He will replace Angelo DiMino, who is retiring.
* Darlene Messinger, principal of W.R. Nelson Elementary School for the past three years, will become principal of Estock School.
* Chris Gregg, principal of Tustin Memorial Academy, will take the top spot at Nelson School.
* Cindy Agopian, the district's director of special education for the past two years, will become principal of Tustin Memorial Academy. Susan Roice, a longtime educator in Riverside, will take over as special education director.
* Karla Wells, principal of Marjorie Veeh Elementary for the past two years, was named principal of C.C. Lambert Elementary, which will become a year-round school in July. She replaces Bill Wingo, who is retiring.
* Kathie Nielsen, a teacher on special assignment in reading, will assume duties of principal at Veeh.
In addition, Foothill High School physics teacher Ed Hepinger was named dean of the school, and English language development teacher Margaret Sanders will become coordinator of that department.