Not really much new information.
The shooter entered the Mall wearing a backpack and went to the restroom for about an hour.
No patrons noticed anything unusual or seamed alarmed on surveillance video.
His phone history/data indicated his last search was for info about an old girlfriend.
(that search info came from a subpoena to the phone provider rather from the phone itself.)
Police said the shooter brought two rifles, a pistol and more than 100 rounds of ammunition to the mall that day.
He fired 24 rounds with one of the rifles.
The first-person shot and killed was entering the restroom as the shooter was exiting, two more at a table in the food court were also shot and killed. A 12-year-old girl had a minor back wound and a 22-year-old woman had a leg wound. Both survived. Several more shots hit around the food court.
The shooter was involved in a fight at school in the past as juvenile.
The shooter's Reddit screen name was turned into the FBI Baltimore office in 2019, as someone with an interest in mass shootings. No posting made any threat.
The FBI contacted the local law enforcement, but the IP address could not be traced to a specific individual
The Apartment complex (1400 residents) used a shared Wi-Fi, preventing tracing the IP address.
At that time there was no indication of any threat being made or any other law being broken.
I watched about the first half hour of the news conference and about last 5 minutes.
A local newspaper has a FaceBook video of the second press conference with the Good Samaritan's attorney.