PORTLAND, Ore. -- As the search for missing seven-year-old Kyron Horman reached its ninth week, grand jury proceedings continued Friday at the Multnomah County Courthouse.
KGW has learned that Skyline Elementary School principal Ben Keefer appeared before the grand jury on Friday.
Earlier this week, investigators asked the Portland Public School district for a list of employees. KGW has learned that several other school employees have been subpoenaed by the grand jury.
C.W. Jensen, a former Portland Police Homicide Detective, told KGW that investigators could have several reasons to call school employees to testify, including as a way to establish the level of security at skyline elementary and whether it was likely that a stranger could have gained access to the school.
Earlier this week, several friends of Terri Moulton-Horman were called before the grand jury. More: Terri's friends subpoenaed
Sources also told KGW that the grand jury was focusing on trying to determine Terri's whereabouts during the day that Kyron disappeared.
Complete Coverage: Search for Kyron Horman
KGW's Anne Yeager and Colin Miner contributed to this report.