Alfred Purcell, 57, was arrested Thursday after he was caught planting ammunition at Southbridge High School in Massachusetts

A biology teacher in Massachusetts has been arrested after he was caught on camera planting live ammunition in a stairwell at his high school.

Surveillance footage captured Alfred Purcell, 57, removing the 9mm bullet from the pocket of his pants at Southbridge High School on Thursday morning before he dropped it on the floor and quickly left the scene.

He returned to the area 10 minutes later and pretended to discover the ammunition, before alerting administrators and sending the school into lockdown.

After reviewing the surveillance footage, police took Purcell into custody where he reportedly told them he planted the bullet it in order to prove 'the school needed metal detectors'.

Purcell has been charged with two counts of the unlawful possession of ammunition, two counts of carrying ammunition on school grounds, disturbing a school assembly, disorderly conduct, and disturbing the peace.

Purcell was captured on surveillance camera peering over the stairwell to make sure nobody was coming, before he dropped the 9mm bullet and walked off

Southwell High School (pictured) was sent into lockdown following the incident

Officers also discovered 102 live rounds of shotgun ammunition in the trunk of Purcell's car. They later learned his license to carry a firearm was expired in his home state of Connecticut.

Following the incident, Chief Shane Woodson of the Southbridge Police Department stated: 'There were no kids that were injured, nobody was seriously impacted by this other than that we went into a lockdown for an hour and we had to investigate a teacher who was doing things he shouldn't be doing'.

Meanwhile, Southbridge High School superintendent Jeffrey Purcell stated: 'This individual acted in a disgusting manner. I feel very badly for our students because it is an adult who failed them'.

Purcell has been ordered to stay away from Southbridge High campus.

He had been told prior to Thursday's incident that his contract at the school would not be renewed, according to WCVB.

The long-time teacher was released on a $500 cash bail following his arraignment.