Las Vegas shooting: Police 'looking for second woman connected to Stephen Paddock'

Authorities have already questioned shooter's girlfriend

Paddock's family said they were stunned to learn he was responsible for the deadliest mass shooting in US history (AP)

Authorities investigating the Las Vegas massacre are reportedly seeking information on a second woman seen with assailant Stephen Paddock.

Police have said that the killer acted alone when he rained down bullets on a country music concert from his room at the Mandalay Bay Hotel, killing 59 and injuring 489.

They have questioned Paddock’s girlfriend, Marilou Danley, but have said she is not a suspect.

However, investigators have broadened their inquiry and are hoping to learn more about a woman spotted with him in the days before he opened fire, according to NBC News. The Las Vegas Metropolitan Police Department did not immediately respond to The Independent’s request for comment.

Citing anonymous law enforcement officials, NBC News reported that investigators are seeking the mystery woman to help them construct a timeline of the days leading up to the attack.

Some details of that timeline have already emerged. Officials have sketched out how Paddock methodically prepared for days after checking into his room, which had sweeping view over the concert ground.

There he stockpiled guns and set up a surveillance system. A raid of his home in a retirement community uncovered another armoury of firearms, ammunition and explosives.

Labelled a “person of interest” by authorities, Ms Danley returned to America from the Philippines yesterday and was questioned by the FBI.

She released a statement through her attorney disavowing any knowledge of Mr Paddock’s plot.

“I knew Stephen as a kind, caring, quiet man,” her statement.

“I loved him and hoped for a quiet future together. He never said anything to me, or took any action that I was aware of that I understood in any way to be a warning that something horrible like this was going to happen.”