HAMPSTEAD, N.C. – A lockdown at three Pender County schools was cleared by quick action from a parent on Tuesday.

• Bryce Sheehan was arrested Tuesday with several knives at Topsail High School.
• Sheehan's mother called police after seeing a disturbing post on his Instagram.
• Alan Edwardo Jr. was also arrested on campus with a gun. 

An alarming Instagram post prompted 18-year-old Bryce Matthew Sheehan’s mother to call authorities.

The post showed two guns and said: "I wonder which one could do more damage?"

Topsail High School was placed on lockdown and Sheehan was arrested after deputies found him in his car with a large knife strapped to his leg and three other knives on him.

Then, reports of someone driving erratically near the school led authorities to 16 year old Alan Edwardo Jr. and a .22 caliber semi-automatic rifle in his vehicle.

Edwardo told authorities that he was planning to stop Sheehan's attack. 

Officials said they’re thankful for the quick response by the parent.

"Because we had the information, we were able to act so quickly that whatever would have happened Tuesday, it did not. And I am grateful to God for that,” said Sheriff Carson Smith.

Authorities say if you know about an attack don't take matters into your own hands, call the police.

Sheehan is charged with possession of a weapon on educational property and jailed under a $25,000 bond.

Meanwhile, Edwardo made his first appearance Thursday on a firearm charge. His bond was upped to $40,000.