Alpharetta police are investigating a violent home invasion last week in which intruders tied up and threatened a family for about an hour before leaving with jewelry and other valuables.

The incident happened shortly before 10 p.m. Thursday at a home on Garrick Point.

According to a police incident report, the homeowner told investigators that he was working on his cars in his garage, with one of the garage doors open.

“As the victim was walking into the house, three males wearing ski masks, gloves and dark clothing stormed into the house behind him,” the report stated. “Two or three of the suspects were armed with semi-automatic handguns and ordered the victim to the floor of the kitchen.”

The suspects then took the man’s ring, Rolex watch and wallet, police said.

“At the same time, the victim’s wife was in the kitchen and attempted to escape via the laundry room door, but one of the gunmen tackled her and knocked her onto the floor,” according to the report. “One of the suspects put a rag in her mouth and dragged her back into the kitchen, where he emptied the contents of her purse.”

The robbers then took the couple upstairs to their master bedroom “and ordered them to lie face down on the floor,” the report said. “The suspects put clothing on top of the victim and his wife and told them not to look at them.”

One of the suspects went to another bedroom, where the couple’s 16-year-old son, having heard the commotion, was hiding in the closet.

“One of the suspects forced open the door, pointed a gun and forced him to the floor,” the report stated.

The gunman asked the son about the location of money and a safe, then moved him into the bedroom with his parents, where all three victims were bound with packing tape.

According to the report, “over the next hour, the suspects ransacked the entire upstairs bedrooms, closets and bathrooms. All of the beds were turned over as the suspects searched for valuables.”

The suspects found and opened the safe, which contained jewelry, then ransacked other rooms of the house in search of valuables.

The victims were eventually able to free themselves from the packing tape, and pressed the panic button on their alarm system. The suspects had fled by the time police arrived.

Alpharetta police spokesman George Gordon said investigators are “working this incident as a top priority.”

Officers have also met with concerned residents of the neighborhood off Kimball Bridge Road, Gordon said.