The citizens of Las Vegas and many more across the entire U.S. are still reeling from the shock and the terror unleashed at a country music festival on the Las Vegas Strip. On Tuesday, investigators have been able to discern that the mass shooting was carefully planned and constructed. However, the search for the shooter’s motives remains murky at best.

Stephen Paddock, 64, is responsible for the brutal murder of at least 59 concert-goers, and injuring another 527. Paddock fired relentlessly on the innocent crowd below him from a Mandalay Bay Resort and Casino hotel room, with shots consistently fired for nine minutes after the first 911 call was received. Paddock shot through his hotel room door at hotel security as they closed in on the room, striking a guard in the leg. Paddock killed himself as SWAT officers went in.

The mystery remains, CNN reports, as to exactly how the retired accountant morphed into the deadliest mass murderer in U.S. history.

In a piece released by The New York Times, Paddock is described as a “high-stakes gambler recognized in the casinos of Nevada.” He held real-estate investments in Texas. His last full-time employment, as an accountant, was 30 years ago. He had been married twice, divorced twice. He had a pilot’s license and even owned two single-engine planes. His neighbors in Mesquite, Nevada said he drew little attention and mainly kept to himself. His close relatives told reporters he didn’t hold strong religious or political views.

Paddock’s father apparently was a bank robber. He escaped from prison and spent the 1970s on the F.B.I.’s most wanted list. Growing up with three brothers, his mother told them their father was dead.

Although “Wanted” posters for Paddock’s father listed he was “psychopathic,” “reportedly has suicidal tendencies” and “should be considered armed and very dangerous,” Paddock’s brothers report he appeared to be nothing of the sort.

“He was a gambler, that was his job,” Eric Paddock, the shooter’s brother, had to say about him. “He was a wealthy guy, playing video poker, who went cruising all the time and lived in a hotel room.”

Las Vegas Metropolitan Police found a cache of weapons in Paddock’s hotel room. They found 23 guns in his room, some of which were set up with scopes and tripods. As police searched Paddock’s property in Reno, Nevada, more weapons were discovered there as well. Clark County Sheriff Joseph Lombardo reported police found five handguns, two shotguns and a “plethora” of ammunition at the property. The compiled total of firearms found between Paddock’s hotel room and his property in Reno is 42.

Paddock also had several cameras placed strategically outside his hotel room. At least one camera was concealed in a hotel service cart outside the room. Sheriff Lombardo said the placement suggested Paddock was “looking for anybody coming to take him into custody.”

“It was pre-planned, extensively, and I’m pretty sure that he evaluated everything that he did in his actions, which is pretty troubling,” Lombardo said at a briefing Tuesday afternoon.

Early information on Monday reported that authorities were searching for a woman they believed was connected to Paddock. CNN reports that police believe Paddock acted alone. Sans accomplices, Paddock’s motives are made much harder to uncover.

Tuesday, authorities continue to search through the debris scattered along the festival grounds where the shooting occurred. Most of the area and the traffic along the southern end of the Las Vegas Strip remained blocked off by police on Tuesday. The venue, described as “frozen in time” by The New York Times, was virtually untouched since the shooting; the only additions were flowers and balloons placed on a median and countless television cameras from all over the world.

The nation learned the names of some of the victims on Tuesday and began to hear stories from survivors. The fact remains, however, that Paddock’s motives remain unknown.