LAS VEGAS (AP) - The Las Vegas gunman meticulously planned the worst shooting in recent U.S. history, researching SWAT tactics, renting other hotel rooms overlooking outdoor concerts and investigating potential targets in at least four cities, authorities said Friday.
But almost four months after Stephen Paddock killed 58 people and wounded more than 800 others with a barrage of bullets from the Mandalay Bay casino-hotel, investigators still have not answered the key question: Why did he do it?
Clark County Sheriff Joe Lombardo released a preliminary report on the Oct. 1 attack and said he did not expect criminal charges to be filed against Paddock's girlfriend, Marilou Danley, who had been called the only person of interest in the case. Investigators believe Paddock acted alone, and he did not leave a suicide note or manifesto.
Paddock, who killed himself before police reached him, told friends and relatives he always felt ill, in pain and fatigued, authorities said.
His doctor thought he may have had bipolar disorder but told police Paddock refused to discuss the possibility, the report said. The doctor offered him antidepressants, but Paddock accepted only a prescription for anxiety medication. He was fearful of medication and often refused to take it, the doctor told investigators.
During an interview with authorities, Paddock's girlfriend said he had become "distant" in the year before the shooting and their relationship was no longer intimate.
When they stayed at the Mandalay Bay together in September 2017, Paddock acted strangely, she told investigators. She remembered him constantly looking out the windows overlooking an area where the concert would be held the next month. He moved from window to window to see the site from different angles, the report said.
She described him as "germaphobic" and said he had strong reactions to smells.
The 64-year-old retired accountant was a high-stakes gambler and real estate investor. He had lost a "significant amount of wealth" since September 2015, which led to "bouts of depression," the sheriff has said. But Paddock had paid off his gambling debts before the shooting, according to the report.
Prior to the attack, Paddock's online searches included research into SWAT tactics and consideration of other potential public targets, including in Chicago, Boston and Santa Monica, California, the sheriff said.
His research also sought the number of attendees at other concerts in Las Vegas and the size of the crowds at Santa Monica's beach. Among his searches was "do police use explosives," the report said.
Four laptops and three cellphones were found inside his hotel suite. On one of the computers, investigators found hundreds of photos of child pornography.
The same computer was used to search for the height of the Mandalay Bay, how to remove hard drives from laptops, the location of gun shows in Nevada and information about several other Las Vegas casinos.