
Clark County, Nevada Sheriff Joe Lombardo released a preliminary report on the Las Vegas shooting on Friday. Gunman Stephen Paddock, who was killed after the attack, pictured above

Investigators have still not discovered what motivated Stephen Paddock to embark on the worst mass shooting in modern U.S. history but determined that he researched SWAT tactics ahead of the massacre and investigated other possible targets, including the famed California beach in Santa Monica, officials said Friday.

They also determined that Paddock acted alone when he opened fire from his high-rise hotel suite, killing 58 people and injuring hundreds, Clark County Sheriff Joe Lombardo told reporters.

Lombardo made public a preliminary report into the shooting and said he does not expect charges to be filed against Paddock's girlfriend, Marilou Danley, who had been previously called a person of interest in the case. Investigators also found that Paddock had possessed child pornography, Lombardo said.

Paddock's online searches before the shooting included research into SWAT tactics and for other potential public venue targets - and he took photographs of some potential sites, the sheriff said. The searches also included the number of attendees at other concerts in Las Vegas and how many people go to Santa Monica's beach.

During the Friday press conference, Lombardo also revealed that police are investigating a person of interest, who is not Danley. Lombardo reiterated, however, that they believe Paddock was a lone shooter.

Paddock's vantage point from the Mandalay Bay, where he carried out the attack, is seen above. He targeted concertogers at the Route 91 music festival across the street

The report included never-before-seen pictures from inside the gunman's suite, which he used to fire down on innocent concertgoers. The photo above includes a picture of the smaller connecting room that Paddock used as a second shooting vantage point

The above picture shows Paddock's minivan, which investigators initially said he planned to use to escape

Several packages of tannerite, an explosive, were found inside Paddock's car

According to the report, investigators found 20 two-pound containers of exploding targets, 10 one-pound containers of exploding targets, two 20-pound bags of explosive precursors, a loaded magazine for an AR-10 rifle, a loaded magazine for an AR-15 magazine, boxed ammunition, suitcases and towels inside Paddock's 2017 Chrysler Pacifica

Mandalay Bay security were first drawn to Paddock's hotel room when they noticed a stairwell door that had been screwed shut (above). A security officer responded to the floor and heard gunshots

Paddock set up a camera on a room service cart outside of his room so he could know when officers were arriving outside his door (straight ahead and on the right)

Above, a view of the covert camera that Paddock his underneath a plate on the food service cart left outside his room

Paddock also set up a second camera in the peephole of the hotel room door, as a second vantage into the hallway

When officers first arrived at the scene, Paddock tried shooting at them through the door to his suite

Paddock used a computer to livestream the feeds from the cameras so he could watch the hallway from inside his suite

By the time they burst into the suite, Paddock had already shot himself dead. Above, a view of the entrance to the larger suite

Pictured above is a previously released photo of the gunman dead on the floor of his hotel suite after the 10-minute shooting

Investigators also included this graphic showing the layout of Paddock's two connecting rooms. Room 32135 was the larger suite, and room 32134 was the smaller one. He shot out of windows on the northeast side of the larger room and on the east side of the smaller room

The sheriff and the FBI have said they found no link to international terrorism. They said they believe Paddock meticulously prepared and concealed his plan to fire assault-style weapons from the 32nd floor of the Mandalay Bay hotel into a crowd of 22,000 people attending the Route 91 Harvest Festival music below.

Paddock fired more than 1,100 bullets, mostly from two windows in the high-rise hotel, Lombardo has said. That includes about 200 shots fired through Paddock's hotel room door into a hallway where an unarmed hotel security guard was wounded in the leg and a maintenance engineer took cover to avoid being hit.

Several bullets hit aviation fuel storage tanks at nearby McCarran International Airport that did not explode. Authorities reported finding about 4,000 unused bullets in Paddock's two-room suite, including incendiary rounds that Lombardo said were not used.

The Mandalay Bay hotel is seen in the top left of this picture, released in the report on Friday

Investigators recovered 23 guns in Paddock's suite. Some of the rifles are seen above

Twelve of the rifles had been fitted with 'bump stock' devices to make them fire faster, similar to a fully automatic weapon

Paddock fired more than 1,100 bullets, mostly from two windows in the high-rise hotel. Above, some of the bullets on the floor, near the window where he shot from

Paddock smuggled a huge array of tools into his hotel room to prepare for the horrific attack

This is the chilling notes Paddock wrote as he calculated the distance to the concertgoers across the street, so he could use the right weapon to target them

Paddock booked two rooms at the Mandalay Bay that connected through the door above. He shot out of two windows, one in the larger room and one in the small room

Pictured above is Paddock's smaller room, and some of the guns found inside

Several bullets hit aviation fuel storage tanks at nearby McCarran International Airport that did not explode

Above, a bullet hole that truck one of the fuel tanks at McCarren

Another item found in Paddock's room and taken as evidence was a blue snorkel mouthpiece attached to some piping. The report doesn't say what the believe this was for

KEY FINDINGS FROM THE CLARK COUNTY SHERIFF'S INVESTIGATION INTO THE MANDALAY BAY MASSACRE Investigators determined key findings as a result of this investigation: Paddock acted alone. Thousands of hours of digital media were reviewed and after all the interviews conducted, no evidence exists to indicate Paddock conspired with or acted in collusion with anybody else. This includes video surveillance, recovered DNA19 and analysis of cellular phones and computers belonging to Paddock. No suicide note or manifesto was found. Of all the evidence collected from rooms 32-135 and 32-134, there was no note or manifesto stating Paddock’s intentions. The only handwritten documentation found in either room was the small note indicating measurements and distances related to the use of rifles. There was no evidence of radicalization or ideology to support any theory that Paddock supported or followed any hate groups or any domestic or foreign terrorist organizations. Despite numerous interviews with Paddock’s family, acquaintances and gambling contacts, investigators could not link Paddock to any specific ideology. Paddock committed no crimes leading up to the October 1st mass shooting. All the weapons he purchased to include all the ammunition, were purchased legally. This includes all the purchases Paddock made at gun stores as well as online purchases. Paddock did not commit a crime until he fired the first round into the crowd at the Las Vegas Village. Reference the 1,965 investigated leads, 21,560 hours of video, 251,099 images obtained and 746 legal notices filed or sent, nothing was found to indicate motive on the part of Paddock or that he acted with anyone else. Security Officer Campos was not shot with a BB gun but rather sustained a gunshot wound from one of the rounds fired by Paddock down the hallway of the 100 wing on the 32nd floor. Security Officer Campos did in fact have a pre-planned vacation to Mexico to go visit his father and Security Officer Campos asked law enforcement for permission to make this trip. One aspect of the investigation focused on Paddock’s financials. The investigation proved Paddock was self-funded through his gambling and past real estate transactions. He was indebted to no one and in fact paid all his gambling debts off prior to the shooting. The investigation revealed several indicators of intent on the part of Paddock. Those indicators are as follows: Paddock had a reservation for a hotel during the Lollapalooza music festival held at Grant Park in Chicago, Illinois during the month of August. Like Route 91, the Lollapalooza festival was held in an open air venue. Paddock specifically requested a room overlooking the venue when he made the reservation. The reservation was cancelled two days prior to the check-in date. Paddock made lodging reservations during the Life is Beautiful music festival held in Downtown Las Vegas, Nevada. The festival was also an open air music venue attended by thousands of people. Paddock requested units overlooking the venue. Paddock reserved three different units during the period and all faced the venue. Paddock was observed in video surveillance transporting several suitcases from his vehicle to the units he reserved. Paddock was alone for the trip and was never accompanied by anyone for more than a casual conversation. Investigators have been unable to determine if Paddock intended an attack during this festival or if he used it as a means to plan a future attack. Paddock conducted several internet searches while planning his actions. Search terms included open air concert venues, Las Vegas SWAT tactics, weapons and explosives. Paddock also searched for various gun stores. The purchasing of over 55 firearms, which were mostly rifles in various calibers, from October 2016 – September 2017. He also bought over 100 firearm related items through various retailers during that period. During a stay in early September 2017, Paddock requested specific rooms that overlooked the Las Vegas Village. According to Danley, Paddock spent time looking at the Las Vegas Village venue from different angles and windows while inside the room. Advertisement

Investigators found 23 guns in the rooms, including 12 rifles that a federal Bureau of Alcohol, Tobacco and Firearms official said were fitted with 'bump stock' devices that allowed rapid-fire shooting similar to fully automatic operation.

Paddock killed himself with a gunshot to the mouth before police reached him. The 64-year-old retired accountant and multimillionaire real estate investor had earned hotel upgrades as a high-stakes video poker gambler at several Las Vegas casino resorts.

Danley was in the Philippines at the time of the shooting.

Clark County Sheriff Joe Lombardo discusses the Route 91 Harvest Festival mass shooting during a news conference on Friday

The report says that Paddock's girlfriend, Marilou Danley, will likely not face charges. She had previously been called a person of interest in the case

Lombardo and Aaron Rouse, FBI agent in charge in Las Vegas, had described Danley as a person of interest in the investigation but not a suspect. She was questioned by the FBI when she arrived in Los Angeles from overseas, and was described as cooperating with investigators.

However, a document filed October 6 and unsealed last Friday by a federal judge in Las Vegas said the FBI considered Danley 'the most likely person who aided or abetted Stephen Paddock.'

Questions have been raised about Danley's receipt in the Philippines of a $10,000 wire transfer from Paddock just days before the shooting.

FBI warrant documents also showed that Danley told investigators that they would find her fingerprints on bullets used during the attack because she would sometimes help Paddock load high-volume ammunition magazines, and that Danley deleted her Facebook account in the hours immediately following the shooting.

The Clark County coroner ruled that all 58 people killed in the attack died of gunshot wounds. Paddock's death was ruled a suicide. Media organizations including The Associated Press are seeking autopsy records that have not been made public.