MARBLEHEAD – Popular Marblehead Veterans Middle School Principal Elizabeth “Libby” Moore is retiring July 1.Moore has spent 28 years as an educator at the Marblehead Village School and the Veterans School, including six as principal, and she helped design the present school when it took over the town?s former high school building. Today it houses 478 students in Grades 7 and 8 and is familiar to most townspeople as the site for Town Meetings.The Marblehead resident said she actually came to her decision last year after a fall left her with a broken shoulder and she had to spend a month at home.?I started thinking, ?I was lucky,” she said Monday. “I have a few years left and I should spend them doing some other things with my husband, my children and my grandchildren. As a principal I have to be at the school day and night and it doesn?t leave a lot of time for other things.”?I am proud of the vibrant and challenging school we have created,” she wrote in a letter announcing her retirement. “I am confident I will be watching MVMS excel over the coming years.” She listed some accomplishments: a new Grade 8 social studies curriculum, a new engineering and technology course and a new integrated physical education-wellness program.On Monday Moore also offered her gratitude for the way “The whole town opened up their hearts to this school. Everyone volunteered, there are people here all the time.”Grade 7 and 8 students are at a turning point, re-evaluating the role of adults in their lives, and many adults, from selectmen down to firefighters, police officers and everyday citizens have volunteered time to come to the Veterans School and spend time with students.?I?m still going to be around,” she added, “I?ll be involved in other activities. Hopefully I?ll be able to mentor some educators and teach classes at Harvard or Salem State University.”Moore said she is looking forward to working with Maass in choosing her successor. Her retirement gives incoming Superintendent of Schools Gregory Maass the opportunity to choose his first major administrator.School Committee Chairman EuRim Chun announced Thursday that the committee has successfully concluded contract negotiations with preferred candidate Gregory Maass, who is currently serving as superintendent of Green Bay Area School district. Maass was chosen as the preferred candidate Feb. 3, and is scheduled to begin his duties officially July 1. Chun declined to release other details, including Maass?s salary, until the contract is officially signed.Superintendent of Schools Paul Dulac is serving until June 30. Dulac said he has posted the middle school principal vacancy and School Business Manager Brian Salzer will head the screening committee, which will include staff and parents.?I will not be involved in the process,” Dulac said.