Paddock committed no crimes leading up to the October 1st mass shooting.
Catherine Lombardo, an attorney for victims of the Las Vegas shooting, also appeared on "Tucker Carlson Tonight".
Lombardo also says a federal grand jury is hearing evidence in a case spun off from the October 1 mass shooting.
The sheriff did not identify the person under federal investigation or say what charges the person might face.
The report included previously unseen photos of the stockpile of weapons found in Paddock's suite.
"Although the investigation to date has not produced any conclusive evidence that Danley aided Paddock, had foreknowledge of his plans, or has been deceptive with law enforcement, this aspect of the investigation is still the subject of intensive review", documents obtained by the Review-Journal read.
In the days after the shooting, some people reported suffering injuries in the hectic rush by thousands to flee the gunfire.
The preliminary report was posted to the police department's website by the end of the press conference.More news: Conte likes Dzeko but Chelsea have made no offer, says agent
Ms Danley also observed him frequently looking out the windows at Mandalay Bay, the hotel overlooking the country music concert where he opened fire, during an earlier stay.
A search warrant affidavit filed in the days after the shooting shows Danley was regarded by the Federal Bureau of Investigation as "the most likely person who aided or abetted Stephen Paddock".
Lombardo and Aaron Rouse, FBI specialist in control in Las Vegas, had portrayed Danley as a man of enthusiasm for the examination however not a suspect. The pursuits additionally incorporated the quantity of participants at different shows in Las Vegas and what number of individuals go to Santa Monica's shoreline.
He also said that the report will shed light on planning of attack, Paddock's research, and how he carried out the attack.
Authorities have yet to uncover a motive in the Las Vegas massacre almost four months after gunman Stephen Paddock loosed a barrage of bullets at those attending an October country music festival on the Las Vegas strip.
In the USA, the Federal Bureau of Investigation says it is looking at a new person of interest in connection with last October's mass shooting at a concert in Las Vegas that left 58 people dead.
It's not protocol to release preliminary reports such as this, Lombardo pointed out, but he wanted to do so because of the public interest in the case.