The FBI is investigating the death of an off-duty deputy sheriff during a botched robbery at a nightclub, which means the alleged shooter might face the federal death penalty.

The FBI's findings will be given to the U.S. attorney's office, which will decide whether to prosecute the case at the federal level.

U.S. Attorney Ed Kubo confirmed the FBI's involvement and said his office would follow the case closely.

"I take these types of cases very seriously when anyone harms any law enforcement official," Kubo said. "We will continue to monitor this case as it moves through the state judicial system. We will make our determination sometime in the future."

He declined to speculate about the death penalty possibility, since the case is currently being handled at the state level, where the death penalty is not an option.

A crime in an establishment that conducts interstate commerce — the deputy was killed in a bar that buys goods from out of state — allows the federal government to intervene.

John Koa Lorenzo Jr., 32, allegedly shot Daniel Browne-Sanchez three times with a stolen .22-caliber Ruger semi-automatic pistol with a silencer affixed to the barrel during a holdup at Osake Sushi Bar and Lounge early Saturday. Browne-Sanchez was shot as he tried to disarm a man who entered the bar and demanded money at gunpoint.

Browne-Sanchez worked at Osake as a bartender's assistant and was off-duty at the time of the shooting. He is the first state deputy sheriff to be shot and killed.

Lorenzo, who is being held in lieu of $1 million bail, faces charges including second-degree murder, kidnapping, first-degree robbery and attempted murder.

On Monday, Kubo said federal prosecutors would have jurisdiction to prosecute Lorenzo and could seek the death penalty for the slaying of Browne-Sanchez, under the Hobbs Act.

VIOLENT TREND

The FBI yesterday said the deadly armed robbery follows a recent trend of increased violent offenses.

"Based on the findings of the FBI's preliminary semi-annual crime report released at the end of 2006, murder, robbery and aggravated assault incidents all increased over the previous year's findings. The Honolulu division of the FBI is obviously concerned by this trend and continues to use all available resources to assist local law enforcement in combating such crimes," said FBI assistant special agent in charge Robert Kauffman. "We are standing by. The county is running the investigation at this time. We will assist and proceed with the federal investigation if the county should request."

Longer term, however, police and law enforcement experts say the crime is an aberration because robberies on O'ahu have generally been decreasing since peaking in the late 1990s.

Through August, there were 616 robberies in the state compared with 841 in 2005, 818 in 2004, 989 in 2003 and 1,072 in 2002.

"It (Browne-Sanchez's death) was a very tragic random act of violence," said Honolulu police Capt. Frank Fujii. "Fortunately, that robbery was not typical of the type of robberies we have here. Most of the robberies (in Honolulu) don't have any violence associated with it."

Reach Peter Boylan at pboylan@honoluluadvertiser.com.