LAS VEGAS (CBSNewYork/AP) — Nearly a week after the deadliest mass shooting in modern U.S. history, investigators continue to search for clues, hoping to answer the question on so many Americans’ minds.

Why did 64-year-old Stephen Paddock open fire on thousands of concertgoers in Las Vegas?

Las Vegas Metro Police say they are following up on more than 1,000 leads.

“In the past terror attacks or mass murder incidents, motive was made very clear by a note that was left, by a social media post, by a telephone call that was made, by investigators mining computer data,” Undersheriff Kevin McMahill said. “Today in our investigation, we don’t have any of that uncovered.”

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Investigators say Paddock’s hotel suite contained a cache of weapons, including AK 47s and AR 15s. Sources told CBS News his arsenal cost well over $50,000.

His car, which was found in the Mandalay Bay Resort and Casino parking garage, also had more than 1,000 rounds of ammunition, plus the explosive tannerite.

As CBS News reported, a note found in his suite included calculations about where to aim in order to be as accurate as possible.

Gun safety advocates gathered Saturday in Union Square, urging Congress not to consider a bill in the SHARE ACT, which would loosen restrictions on gun silencers and deregulate sales of armor-piercing bullets.

If passed, Congressman Carol Maloney says the carnage in Las Vegas would have been even worse.

“He would have been able to kill more people before you would even known where he was,” she said. “This is the height of ridiculous, a lack of common sense. We have to stop this bill from going forward.”

Manhattan District Attorney Cy Vance also demanded that a bill expanding concealed carry rights gets dropped, too.

“Anticipate many, many, many concealed weapons coming into our communities. The cops are going to be on the front line. It may, in fact, force them to be more aggressive in order to deal with these weapons,” he said.

Federal agents have started hauling away thousands of personal items left behind when the shooting spree happened, including baby strollers, backpacks and purses. Authorities say they plan to return them to people in the coming week.

Also Saturday, Vice President Mike Pence spoke at the City Council Chambersin Las Vegas and attended a unity service to honor the victims of Sunday’s mass shooting.

“It was a tragedy of unimaginable proportions,” he said. “Those we lost were taken before their time, but their names and their stories will forever be etched into the hearts of the American people.”

The Saturday afternoon service came after dozens of people — many wearing shirts that said “Vegas Strong” — marched from Mandalay Bay to City Hall. Following speeches from Pence and other politicians, doves were released into the air, flying in a wide arc and then disappearing into the distance as someone shouted, “God bless America!”

“On Sunday night, Las Vegas came face-to-face with pure evil, but no evil, no act of violence, will ever diminish the strength and goodness of the American people,” Pence said. “In the depths of horror, we will always find hope in the men and women who risk their lives for ours.”

Volunteers came together to build a community healing garden, which opened Friday night. The park includes a Wall of Remembrance and 58 trees planted for each of the victims who lost their lives.

(© Copyright 2017 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)

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