Los Angeles police believe Nerses was the shooter who killed four men and injured two others on April 3 at the Hot Spot Cafe.
There was no word on what role his brother may have played, but marshals say both men had murder warrants out on them.
The violent crime shocked the quiet Valley Village neighborhood.
"We have friends come by here every minute. Morning and afternoon, the children in the neighborhood walk past this place. So, to have something like the Good Friday massacre happen in your own neighborhood is pretty chilling," said Valley Village resident John Heaner.
Police say Nerses was participating in a birthday celebration at the restaurant when an argument got out of hand. Nerses opened fired with a semi-automatic handgun, striking the men. Multiple bullet holes pierced a side wall.
"I thought it was a terrible thing. I don't know what would cause people to do that, but I was just relieved that it wasn't a random shooting," said Chris Saphire, another Valley Village resident.
Police used surveillance video to identify Nerses as the gunman, and authorities have been searching for him for nearly two weeks.
A few days ago, investigators with the U.S. Marshal Service were led to Washington state. Now the two men are behind bars, residents are relieved.
After being open for several years, the Hot Spot Cafe is now closed indefinitely.
"It was a neighborhood restaurant and I work from home so often times, I'd bring clients over there, and they were just great guys," said Valley Village resident Eileen O'Farrell.
In a separate case, Nerses is also facing federal charges for possessing and dealing firearms. It's unclear whether he and his brother will be brought back to California to face the charges against them.