ROYAL PALM BEACH, Fla. (CBS12) — Palm Beach County Sheriff Ric Bradshaw said the man who killed a grandmother and one-year-old boy at a Publix store in Royal Palm Beach made comments on Facebook that he wanted to kill people and children.

Bradshaw spoke Friday afternoon at a news conference on Thursday’s deadly shooting.

According to the sheriff’s office, Timothy J. Wall, 55, killed a 69-year-old grandmother and a toddler as the little boy sat in a Publix shopping cart, in the produce section of the store.

At the news conference, investigators presented their timeline of events, pieced together through security camera footage and interviews with more than 30 witnesses.

Deputies say the victim’s are seen entering the store’s produce department at 11:30am and Wall enters the same part of the store a minute later. Surveillance footage shows Wall appearing to watch the victims before approaching, according to a PBSO media release.

Then, at 11:34am, investigators say Wall can be seen walking up to the toddler, shooting and killing him. The grandmother quickly enters into an altercation with the gunman, briefly jamming the gun, before she is pushed to the ground and also shot.

One witness told 911 operators he saw part of the shooting.

Wall took his own life seconds after shooting the grandmother, according to deputies.

Deputies credit the grandmother with quickly starting a struggle with the alleged gunman and briefly disabling his weapon. Investigators told reporters Friday they believe the grandmother may have saved more lives by taking on the suspect.

Investigators found no connection between Wall and the shooting victims, or a motive.

Bradshaw said the shooting could’ve been prevented had someone spoken up about the threatening Facebook posts.

“There was a chance that this could be stopped,” said Bradshaw. “He’s on Facebook. He has said, ‘I want to kill people and children.’ He has friends, obviously, they saw that.”

Wall’s ex-wife, according to the sheriff’s office, said he had been acting strange, paranoid, and believed he was being followed.

“This tragedy fits the profile across the United States when these things happen,” said Bradshaw. “A, somebody knew about it, that bad things were gonna happen with this guy. And number two is obviously there’s some mental unstableness involved in this.”

The sheriff says detectives are looking into the gun used in the shooting and how Wall obtained it.