Sergeant Daniel Murray and his son, Bryan, went to the CVS in Runnemede, New Jersey on Monday night to buy some vitamins and shampoo. They never expected stopping a robbery would be part of their shopping plans.

It was around 8:30 p.m. when they were checking out and saw masked man running toward the store's front door. Moments before, police said the suspect, identified as 27-year-old Matthew Donahue, forced pharmacists to give him about $11,000 in OxyContin prescription pills at knife point.

A fellow shopper yelled to stop the guy.

"His timing was terrible ... He literally ran right at me," said Murray as he described the event with a chuckle.

Off-duty and in his sweats, Murray acted instinctively and grabbed Donahue before he could get to the door. Bryan jumped in and the two wrestled with the suspect, hitting the store's anti-theft antennas and dislodging the automatic doors, before getting him on the ground.

Uniformed officers arrived on the scene within 30 seconds to place Donahue under arrest.

Donahue, of Gloucester Township, faces several charges including robbery, aggravated assault and unlawful possession of a weapon. He is being held on $100,000.

Murray, who's lived in the town all his life, recalled the event as if it went down in slow motion. He said that police training teaches you to be ready at all times.

"It was just a natural reaction for me to get involved," he continued. "That’s why I was impressed with my son and the resident for jumping in and doing what was right."

Good training for the 18-year-old who is interested in becoming an officer, just like his father.