Update 1:50 p.m.: The lockdown at Chaminade College Preparatory high school has been lifted and those on scene said a student with a boom microphone had been mistaken for the shotgun, according to NBC Los Angeles.
Police said the student was carrying a tripod.
Chaminade College posted a message on its website:
The LAPD has lifted the lockdown at our West Hills (high school) campus and has informed us that it is safe to release students.
We would like to thank all students, faculty, staff and parents for their support and cooperation during this time.
10:42 a.m.: Chaminade College Preparatory high school in West Hills was placed on lockdown while police investigated reports of a person with a shotgun on or near the campus, according to wire services and NBC Los Angeles.
The school posted a message on its website:
"The High School Campus is currently on lockdown. All students and faculty are safe. Please stay away from the campus until we give the all clear. We will provide more information as soon as possible."
The man was sighted around 9:40 a.m., according to NBC L.A. The Los Angeles Police Department’s Topanga Division was investigating the reports, Officer Susan Torres told NBC L.A.