LAS VEGAS (AP) -- The NAACP in Las Vegas wants a federal probe and the American Civil Liberties Union of Nevada is calling for an independent investigation of Las Vegas police practices after a police shooting that killed an unarmed Gulf War veteran behind the wheel of his car in a condominium complex.

The calls for outside oversight came days after Sheriff Douglas Gillespie pleaded for patience from the public and promised a thorough internal investigation of the Monday morning slaying of Stanley Lavon Gibson.

Police said Gibson, 43, rammed his vehicle into police cruisers after officers were called late Sunday to a report of an attempted condominium break-in.

Frank Hawkins Jr., president of the Las Vegas chapter of the National Association for the Advancement of Colored People, noted that Gibson was black and pointed to what he called "an unprecedented number of questionable deaths" at the hands of Las Vegas police.

"There have now been 12 deaths at the hands of the police this year alone," Hawkins said. "Local authorities have proven either unwilling or unable to address what appear to be either rogue or dangerously incompetent officers within the police department operating with impunity."

The U.S. Department of Justice should investigate and make public its findings, Hawkins said.

ACLU chief Dane Claussen called the shooting "deeply troubling" and said it "fits into a long pattern of shootings of persons, many others of whom also were unarmed, who were not an immediate threat to anyone."

Las Vegas police haven't taken sufficient steps to limit shootings and aren't properly investigating them, Claussen said.

Gibson's friends and family members said he had a troubled personal history, was suffering from cancer he blamed on his Army service, had recently had his Veterans Affairs disability payments reduced, and was due for sentencing on an assault charge after an argument with a Veterans Affairs doctor.

Gibson's wife, Rondha Gibson, has told reporters that her husband ran out of anxiety medication and was prone to paranoid delusions and anxiety, with fears that people were after him.

Neighbors' videos show officers firing shots into the vehicle after it spun its wheels while wedged between police cruisers.

Las Vegas police on Wednesday identified the four patrol officers involved in the shooting as officer Jesus Arevalo, officer Malik Grego-Smith, Sgt. Michael Hnatuick and Lt. David Dockendorf. Each is on paid leave pending the internal investigation.

The Las Vegas Review-Journal reported that Gibson and his wife had moved into the condo earlier this month and he might have been confused about where he was when he confronted police.

Gibson's Army discharge shows he separated from the service in 1992. He blamed his cancer to exposure during Operation Desert Storm to depleted uranium from armor-piercing shells used by M-1 tanks.

Department of Veterans Affairs medical records showed Gibson underwent five surgeries for a form of adenoid cancer that left his jaw disfigured and had spread to a lung.

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