After more than three months, investigators have not uncovered a motive in the Las Vegas mass shooting during the Route 91 Harvest Festival, Associated Press reports.
Clark County Sheriff Joe Lombardo told reporters Friday that gunman Stephen Paddock is believed to have acted alone in the October 1 shooting from Mandalay Bay Resort and Casino. They have not determined why he opened fire from his high-rise hotel suite, killing 58 people and injuring hundreds.
In addition, no charges are expected to be filed against deceased shooter Paddock's girlfriend, Marilou Danley, who was previously called a person of interest in the case.
Authorities found that Paddock conducted extensive online searches for police and SWAT tactics and considered other potential targets before he unloaded nine minutes of consecutive gunfire on concertgoers. Investigators believe he had searched for several other public venues and took photographs of other potential sites.
A preliminary report about the shooting showed Paddock searched for multiple outdoor concert venues, the number of attendees at other concerts in Las Vegas and the number of people who visit the beach in Santa Monica, California. The report also claimed Paddock searched for information about several other hotels in Las Vegas.
Lombardo added that the investigation found Paddock had possessed child pornography.
The sheriff's briefing Friday morning comes after a lawyer for the police department asked a Nevada state court judge Tuesday to keep search warrant documents sealed because charges are still being investigated.
A department spokeswoman said criminal charges could relate to items discovered while investigators combed through vehicles, cell phones, online usage and email accounts belonging to Paddock and, at the time, Danley.
The Las Vegas Review-Journal reported Tuesday that other charges related to the case could include people who may not have followed proper firearm sales procedures when selling to Paddock, or anyone who helped him modify his slew weapons.
Paddock modified some of his firearms with an accessory known as a bump stock, which allows a semi-automatic rifle to fire bullets faster than manufactured.
Paddock killed himself via a shot to the head following his spray of gunfire on festival attendees on the Las Vegas Strip. His remains were cremated and given to brother Eric Paddock, according to a statement from Clark County Coroner John Fudenberg. Eric picked the remains up in Las Vegas and will take them back to his home in Florida, where they will be locked in a safe deposit box at the bank, he said.