Less than a year after hiring a new high school principal, Jacksonville City Schools is searching for a replacement. Board of Education members last night voted to accept the resignation of Jacksonville High School principal Bill Singleton. Superintendent Mark Petersen says Singleton resigned Friday to deal with a family medical issue. Peterson says he regrets the system is losing Singleton, but that his office has received dozens of applications, and he hopes to hire a new principal by the end of July. Before coming to Jacksonville last summer, Singleton worked for five years as the assistant principal at Rome High School in Georgia.