Vancouver Police have arrested a man with a long criminal past, and have charged him in the hospital theft of Agnes Ulmer's priceless rings.

The arrest ofTracy Lloyd Caza, 47,  comes after a set of family rings going back seven generations were stolen right off the fingers of an ailing 90-year-old woman. At the time the woman was recovering in hospital from a leg amputation.

On Saturday, a man walked into Agnes Ulmer's room at the Vancouver General Hospital and offered to take her jewelry for a cleaning. Ulmer, who was still medicated after her amputation, agreed.

The man started by taking the ring that belonged to Ulmer's mother and ended with the wedding band Agnes had worn for nearly 70 years.

"Well, he said, 'I'll have them cleaned too'," Ulmer told CTV British Columbia.

The suspect, who was caught on surveillance cameras, never came back. The crime bore the hallmarks of a thief who knew where to go, what to take, and who to prey on.

"We're looking at someone with a long history of crimes like this. They've just been keeping with that pattern (and) have victimized a lot of elderly people in Vancouver," said Vancouver Police spokesperson Jana McGuinness.

In 2002, Caza walked into a seniors' care centre in North Vancouver and stole rings from resident Pauline Moore.

"He shouldn't be doing this to people in a home like this or anywhere because we're very vulnerable," Moore says.

In that case, police noticed Caza looked a lot like a man caught on surveillance two years earlier. Court officials describe him as a "frequent flyer" -- someone who is in and out of court on a regular basis. He's well known to police.

Along with charges in connection with Ulmer's rings, Caza is also accused of trying to defraud another senior Thursday, the day before he was caught and less than a week after allegedly swindling Ulmer.

Caza has a long criminal past. In 1999, he was convicted of theft in New Westminster, a Vancouver suburb. Then in 2002, he had convictions for theft, assault, and break and enter. More convictions for theft followed a year later. More recently, he was convicted in 2006 of break and enter in Vancouver.

Caza will remain behind bars on the latest charges until his next court appearance next week.

Meanwhile, Ulmer will remain in hospital recovering from her amputation. The arrest has given her little consolation. Police haven't recovered her rings.

"I want my rings. Please," she pleaded in a soft voice from her hospital bed.

With a report by CTV British Columbia's Carrie Stefanson