BUFFALO, N.Y. — Local authorities are providing an update on Saturday's deadly attack at the Tops on Buffalo's Jefferson Avenue that left 10 people dead.

Buffalo police say the suspect, Peyton Gendron, 18, of Conklin, was in the area of the store a few months ago. The chief says it appears the suspect visited in early March.

The alleged shooter remains in custody on suicide watch.

The special agent in charge of the FBI office in Buffalo says the processing of such a large scene will take time.

"The FBI laboratory at Quantico has provided advanced tools and teams trained in special techniques that can help map the location, can be used to create digital models, physical models and mapping the trajectory of bullets," said Special Agent Stephen Belongia. "This process is painstaking. It takes time and we will continue as quickly as possible to process that scene so it can be released back to the community which relies on this grocery store so much."

Buffalo Mayor Byron Brown and Erie County District Attorney John Flynn also talked a bit about apparent copycat threats made online, including an arrest made for an alleged threat on Sunday. They say a Buffalo man is facing a felony charge after allegedly making threatening phone calls to a local pizzeria and a brewery in which he referenced the mass shooting at Tops.