LAS VEGAS — Read the latest on the Las Vegas shooting with Friday’s live updates.

The National Rifle Association on Thursday endorsed tighter restrictions on devices that allow a rifle to fire bullets as fast as a machine gun — a rare, if small, step for a group that for years has vehemently opposed any new gun controls.

Twelve of the rifles the Las Vegas gunman, Stephen Paddock, had in a high-rise hotel suite when he opened fire on a crowd on Sunday were outfitted with “bump stocks,” devices that allow a semiautomatic rifle to fire hundreds of rounds per minute, which may explain how he was able to shoot so quickly, killing 58 people and wounding hundreds of others. The federal Bureau of Alcohol, Tobacco, Firearms and Explosives has ruled that bump stocks do not violate laws that tightly limit ownership of machine guns, and some lawmakers have called for them to be banned.

The bureau should revisit the issue and “immediately review whether these devices comply with federal law,” the N.R.A. said in a statement released Thursday. “The N.R.A. believes that devices designed to allow semiautomatic rifles to function like fully-automatic rifles should be subject to additional regulations.”

• Late Thursday night, the Clark County Coroner’s office released the names of the 58 victims killed in the attack. They include 36 women and 22 men. The oldest was 67, the youngest 20. Read more about the victims from our reporters.

• Investigators were still struggling on Thursday to understand what motivated the gunman to open fire on concertgoers at the Route 91 Harvest Festival. The F.B.I. continues to search electronic devices belonging to Mr. Paddock, but investigators have not found a manifesto or signs that he held extremist views.

• A note the gunman left on a table inside his suite at the Mandalay Bay Resort and Casino had numbers written on it, Sheriff Joseph Lombardo of the Las Vegas Metropolitan Police Department said in an interview on Thursday. He said the authorities were trying to determine what the numbers meant, but the sheriff said the document was not a suicide note.

• Mr. Paddock may have scouted other locations before targeting Las Vegas, including Fenway Park in Boston, the Lollapalooza show in Chicago and the Life Is Beautiful music festival in Las Vegas.

• Investigators have identified 47 firearms belonging to Mr. Paddock, including many that he bought in past months. Sheriff Lombardo said on Wednesday that the authorities wanted to know if something happened in his life that led him to stockpile weapons.

• Mr. Paddock fired at least two rifle rounds that struck a jet fuel tank on the western perimeter of McCarran International Airport, an airport spokesman said on Thursday. But the authorities do not believe the gunman targeted the tank.