East Lyme – An investigation into a spent shell casing found at the high school this morning revealed “no reason for any further concern,” according to Superintendent of Schools Jeffrey Newton.

The casing was discovered in the cafeteria by a student around 7:57 a.m. and was immediately reported to security, Newton said in a phone interview Thursday. He said investigators surmised it was accidentally dropped by a student or staff member.

East Lyme police Chief Mike Finkelstein said it was a casing for a .223 caliber rifle.

Newton sent a letter to parents around 9:15 a.m. to let them know the shell casing had been discovered and an investigation had been completed.

Newton said members of the high school’s security staff and School Resource Officer Don Hull of the East Lyme Police Department looked at video footage and talked with students to try to figure out how the shell casing got there. He said there was no conclusive video footage showing the item falling out of someone’s pocket but that “all evidence supports” the conclusion.

Administrators and security staff members at the other schools in town were alerted out of an abundance of caution, according to Newton. He told parents he would let them know if more information emerges or the district is made aware of any other concerns.

Finkelstein said he’s dealt with multiple situations during his career involving casings accidentally dropped by students, especially when he worked in Ledyard for 25 years.

As recently as June, Ledyard police were called to the town’s middle school after a spent shell casing fell from a student’s backpack. The principal at the time called it an example of the effectiveness of the “see something, say something” public safety method.

e.regan@theday.com