Two brothers accused in a quadruple shooting were arrested as this city struggles to rein in crime after Hurricane Katrina, police said Friday.

The pair had been involved in a long-standing dispute with the men who were gunned down last month in a neighborhood not far from the French Quarter, police Superintendent Warren Riley said.

On Friday, Kevin Amison, 21, turned himself over to detectives a day after his younger brother, Raymond Amison, was arrested. Each was booked on four counts of first-degree murder.

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The Amison brothers have denied any involvement in the shootings.

"I've been gone since the 24th," Kevin Amison told reporters as he was escorted into jail Friday night in handcuffs. "I was in Atlanta."

Police said witnesses identified the Amisons as the two men who walked by an abandoned house and opened fire on three brothers — 16-year-old twins and a 21-year-old — and their 39-year-old friend sitting on the porch July 28.

The quadruple killing reinforced fears that crime is making a strong comeback in this city struggling to recover from Katrina. July saw 21 murders, which is just under the monthly average of homicides before Katrina hit and dispersed the city's population. There are still far fewer people living here than before Katrina.

Officials say the crime wave could hurt the city's rebuilding efforts if it's not stopped.

Steps have been taken to combat crime. In June, Gov. Kathleen Blanco dispatched about 300 National Guardsmen and 60 state troopers to help city police. That came after five teenagers were killed in a single attack.

On Thursday, U.S. Sen. Mary Landrieu asked the Justice Department to send in more federal agents and prosecutors to cope with the rising violence. Landrieu suggested that authorities use federal racketeering laws against gangs and drug rings.

Mayor Ray Nagin's office said it would announce additional steps Monday to improve the city's justice system. Problems facing police and prosecutors include getting witnesses to testify, a backlog of cases and the destruction of courtrooms and evidence.