A wave of bank robberies is breaking over the Texas capital city, and while the uptick in heists has authorities concerned, they're not exactly on the lookout for a gang of savvy bandits.

Austin banks have been robbed 30 times so far this year, a remarkable spree given that during all of last year, only 18 such crimes were reported. Still, the spike seems far from organized.

"Most of them aren't what you would call professional," said Austin Police Lt. Charles Black.

Quite the contrary: Nine suspects have been arrested in 20 of the robberies, which have yielded sums ranging from $400 to $10,000. Some have bumbled their way to easy capture, or kept their patterns predictable enough to lead police right to them.

And most -- white or Hispanic males in their 30s and 40s -- are motivated by the need for quick drug money, Black said.

"Historically, Austin has not had a lot of bank robberies," Black said. "That's why we've been somewhat shocked by the number we've had this year."

"Cowboy Bandit" Ernest Rodriguez Jr., of San Antonio, is charged with robbing five Austin banks this year before his April 15 arrest. The nickname came about after bank surveillance cameras showed a robber wearing a large cowboy hat that concealed part of his face.

Rodriguez's criminal record includes an eight-year prison sentence for theft and drug possession.

Rodriguez, 44, kept authorities guessing for two months, hitting one bank after another while as many as 60 officers and employees worked to stop him, Black said.

A computer program was developed to identify the robber's likely next target, calculating similarities with other banks that had been robbed, such as the lobby layout and the proximity to getaway routes. The FBI assisted in the investigation.

Rodriguez was finally caught at the Travis County Credit Union, where two plainclothes officers waited for him. He now faces up to 20 years in prison on each of five counts of bank robbery and another 10 years on a charge of being a convicted felon in possession of a firearm.

Another suspect, Thomas Thompson, was also charged in five robberies. Thompson told investigators he went on his two-week crime jag in February to support a drug habit, Black said.

Jack Levin, director of the Brudnick Center on Violence at Northeastern University in Boston, draws a direct link between the war on drugs and the spike in bank robberies. He said many low-level dealers and users locked up for a few years on drug charges may now be returning to the streets.

"They are coming back into the community," Levin said. "They've graduated from the drug trade."

Austin's latest bank robbery occurred June 9 when two men wearing baseball caps and bandannas to conceal their faces brandished a weapon at a Southwest Austin credit union and fled with an undisclosed amount of cash.

What made that robbery unusual was that a weapon was used; most of the thefts this year did not involve weapons. The robbers either demanded money or slipped a note to the teller. Some fled in cars, others on foot. A few were caught right away.

One robber took his pants off about a block from the bank, hoping a change of clothes would confuse witnesses and police. But he left his wallet and driver's license in the pants pocket. "We got him within an hour," Black said.

Another robber was hardly a block away when a dye pack hidden in the money exploded on him. Police were still arriving on the scene when they spotted the robber and arrested him.

Joe Olivas, vice president of security for Wells Fargo, which has had seven Austin branches robbed this year, said the company trains employees to watch for suspicious behavior and to react during robberies.

"We discourage anybody, either employee or customer, from taking action that would be a danger to themselves or anyone around them," Olivas said.

Despite security cameras, most robbers don't wear masks or disguises, Olivas said.

"Most bank robbers want to walk into any financial institution and go unnoticed," he said. "They want to walk up and take the money."

Ernest Rodriguez Jr., of San Antonio, is charged with robbing five Austin banks this year before his April arrest.