Authorities believe they have identified a serial bank robber who has evaded them for more than a year while pulling off heists disguised as a woman, a wounded soldier and a hospital worker among other masquerades.

A federal arrest warrant was issued Monday for 40-year-old Michael Rosario after Honolulu Police Department detectives and FBI agents alleged that he was the weapon-toting thief in nine bank robberies. Police said they are investigating whether six other robberies might be linked to Rosario.

For the past two days, officers with the police department's specialized services division have swept through neighborhoods in Kalihi and Pearl City looking for him, police said.

"He should be considered armed and dangerous," said police Capt. Frank Fujii.

Fujii said Rosario's picture is now plastered "all over the place" and that he should "turn himself in."

Rosario has two prior convictions, one for first-degree terroristic threatening and a misdemeanor charge of abuse of a household member stemming from a May 31, 2005, arrest.

He was sentenced to five years of probation Jan. 17.

A serial bank robber known for wearing elaborate disguises has been hitting O'ahu banks since last October.

He has dressed up like a nurse in hospital scrubs, a construction worker, a security guard and a blond woman.

In a few, but not all of the robberies, the man tore off part of his disguise as he fled, police said, adding that he has used a gun, a pocket knife and a stun gun.

He has hit several different financial institutions on O'ahu, including American Savings Bank at least twice.

"For our branches, he's become a known enemy," said Abel Malczon, senior vice president for bank operations.

American Savings has circulated a picture of the robber among its branches and have made sure all employees are aware of the bank's security procedures. Malczon said other steps have been taken but wouldn't discuss details.

The serial bank robberies have helped push up the number of heists on O'ahu. Through May, the number of bank robberies in Honolulu already had matched last year's total of 23.

Honolulu remains relatively tame compared with Mainland cities, a federal law official said.

"It doesn't take but one person getting involved with a dozen bank robberies in a town like this to make it look like there is a huge increase in the number," said Charles L. Goodwin, special agent in charge of the FBI's Ho-nolulu division. "If you go to any city on the Mainland of a size comparable to Honolulu ... you'll see at least four times as many bank robberies and more incidents with guns that fortunately we just don't have here. Bank robbery is not a very lucrative profession when you consider the risks of being caught (on an island) and the penalties."

Most bank robbers in Hawai'i make off with $500 to $1,000, police said. First-time bank robbers face up to 18 months in federal prison if no weapon was used, and up to seven years if a gun is pulled.

In general, Honolulu police say, more than 95 percent of all bank robberies on O'ahu are solved through CrimeStoppers tips. However, the number of arrests last year was not immediately available yesterday, police said.

Reach Peter Boylan at pboylan@honoluluadvertiser.com.