Forensic technicians probed their way Monday through a southwest Medford bank that had been burglarized over the weekend by unknown thieves who also gained entry into the bank's vault, authorities said.

Forensic technicians probed their way Monday through a southwest Medford bank that had been burglarized over the weekend by unknown thieves who also gained entry into the bank's vault, authorities said.

"It's a very unusual case," Medford police Lt. Tim Doney said. "We get bank robberies, but bank burglaries are very unusual events, in this area at least."

Police declined to reveal whether the thief or thieves made off with any money or financial documents from the Chase Bank at 81 E. Stewart Ave. in what police have categorized as a "substantial burglary."

"There are items missing, but we're not going into details of what they are," Medford police Deputy Chief Tim George said. "We're still waist-deep in this thing."

Investigators believe the bank was burglarized sometime between 1 p.m. Saturday and 8:30 a.m. Monday.

Forensic technicians from the Medford Police Department and the Oregon State Police Crime Lab spent most of Monday going through the bank looking for any clues about the crime, George said.

"We still have a lot of crime scene work to do," George said.

Investigators also were looking for possible witnesses who saw anyone or anything unusual at or around the bank over the weekend, Doney said.

"We're scouring the neighborhood out there for any potential leads," Doney said.

The FBI has joined the case, and investigators remained mum Monday about details of the crime to preserve the integrity of the investigation, Doney said.

Doney refused to discuss features of the bank's security system, including how or even whether the system was bypassed.

Doney also declined to say how the bank's vault was entered.

"At this point, we probably have more questions than answers," Doney said.

Employees coming to work around 8:30 a.m. discovered evidence of the burglary, and police were notified about 10 a.m., police said.

George said he did not know why bank authorities waited until then to telephone police, but added that Chase officials were cooperating with the case and that the delay was not considered suspicious.

Police have notified other area banks of the burglary and have begun querying other police jurisdictions in search of similar crimes, Doney said.

Anyone with information about the case is urged to call 774-2230.

In late 2003 and early 2004, a burglar used a pry bar to break into four bank branches in Medford, Eagle Point and Ashland. A string of similar burglaries were committed in Josephine County.

Delbert Jackie Cooper, now 54, pleaded guilty in 2004 to single counts of second-degree burglary and second-degree criminal mischief in connection with those burglaries and was sentenced to prison.

Reach reporter Mark Freeman at 776-4470 or mfreeman@mailtribune.com.