SPOKANE, Wash. -

Spokane County Sheriff's deputies have broken up a sophisticated check forgery ring that, due to the way they operated, should have you looking for new ways to protect your identity.

In some instances, victims paid utility bills with a check they had put in their mailbox while other victims had their cars prowled but didn't realize their accounts had been compromised until it was too late.

Car break-ins are up in Spokane and reach their peak just before Christmas but Cook family thought their thief had overlooked their checkbook until three weeks later.

"Me and my wife were checking online our bank statement and there's a couple of checks cashed that we didn't remember making," Wes Cook said.

Numerica Credit Union provided the Cooks their canceled checks but nothing about them looked familiar.

"It was a completely different name, address, but the routing and back account number were the same," Cook said.

Only then did they realize a thief had taken a single check during a break-in.

"We had the checkbook still, but they flipped through to the back of the book and took out a check from the back we so we didn't notice it at the time," Cook said.

Detectives say that gave Tim Jacobsen time to print up his own checks and begin buying big ticket items at places like Best Buy.

"Basically what the suspect was doing was he had an elaborate way to make fake driver's licenses for all 50 states and he would make them for himself and other folks," Spokane County Sheriff's Deputy Craig Chamberlin said.

Because those other thieves got half of every check they passed, a small army of them also started stealing outbound mail.

"Do not put your out-going bills that have your personal checks in the mailbox with that red flag up. Take the time to drive to the post office and drop them off in a secure blue bin," Chamberlin warned.

Jacobsen has been arrested and booked into the Spokane County Jail on a single charge of 1st degree theft. More charges may follow. Numerica Credit Union refunded the money the Cook family lost in this scam.