Later, the White House said, he was to meet with "civilian heroes" and first responders who were at the scene when Stephen Paddock, a 64-year-old gambler and real estate investor, opened fire from the 32nd floor of the hotel at a country music festival going on below.
The father of Stephen Paddock, the man believed to be responsible for the shooting that killed 58 people and injured over 500 more, was once named to the FBI's Top 10 Most Wanted List.
Investigators at the hotel from which Paddock launched his assault found no fewer than 23 guns, including a Kalashnikov and AR-15 assault rifles, and a vast stockpile of military grade.223 calibre ammunition.
Danley's sisters said Paddock bought her "a cheap ticket" to the Philippines, her home country.
Marilou Danley's lawyer read the statement to reporters on Wednesday in Los Angeles, where she was questioned by Federal Bureau of Investigation agents about gunman Stephen Paddock.
Paddock was using her identification leading up to the shooting. If the suicide didn't destroy Paddock's brain, experts may even find a neurological disorder or malformation, he said.
Meanwhile, the girlfriend of Paddock says she had no advance knowledge of what he was planning.
Danley flew Tuesday to Los Angeles from the Philippines and has been cooperating with authorities, Rouse said.
His trip to Las Vegas will be the first time he has had to deal directly with the tragic aftermath of deadly gun violence that has routinely claimed hundreds of lives in recent years.
The cameras Paddock set up at the Mandalay Bay hotel casino were part of his extensive preparations that included stockpiling almost two dozen guns in his room before opening fire on the concert below.
"As the President comes here, he looks at the victims, he looks at the mothers burying their children and the children burying their parents, this is exactly the time to remember this episode and have these kinds of hard conversations", Rosen said.
Las Vegas Sheriff Joe Lombardo, speaking at a Wednesday night news conference, said he remains unconvinced.
As for what motivated the actions of his brother, Eric Paddock said he and his family are "still just completely befuddled".
The timeline of what occurred the night a man fired shots into a crowd of people at a Las Vegas concert was revealed Wednesday showing that it took officers 75 minutes to enter the hotel room where the suspect was located.
Earlier, Trump used a brief address from the White House to call for unity in the aftermath of the deadliest mass shooting in modern us history, calling it an "act of pure evil". The Sunday night rampage by Stephen Craig Paddock killed at least 59 people and injured 527, some from gunfire and some from a chaotic escape.
An FBI official in Las Vegas said no one has been taken into custody.
Authorities have seized 47 firearms from three locations, they said late Tuesday.
Marilou Danley, Paddock's girlfriend, issued a statement Wednesday afternoon through her attorney, Matt Lombard.
"This investigation is not ended with the demise of Mr. Paddock", the sheriff said.