Orange County Sheriff John Mina said Friday that there is a good reason additional charges have not yet been filed against 19-year-old Keith Melvin Moses, the suspect in three Pine Hills shootings Wednesday that resulted in three deaths, including Spectrum News 13's Dylon Lyons.

Addressing the delay, he said officers are working to make this the strongest case possible. Since Moses is already in jail on a first-degree murder charge connected to the Wednesday morning shooting death of 38-year-old Nathacha Augustin, Mina said investigators are taking their time to make sure the case in the pair of afternoon shootings is airtight.

"I have 100% confidence that he’s the one that did this, that he will be prosecuted for this and that he will be convicted," Mina told Spectrum News.

Investigators say Augustin was found shot to death at 11:14 a.m. Wednesday in the 6100 block of Hialeah Street. 

In her killing, the sheriff said Moses was in a car after being picked up by his cousin when he allegedly opened fire on Augustin, who was also in the vehicle.

After the shooting, Moses is accused of fleeing on foot before emergency personnel were able to respond to the scene.

Moses is also accused of killing Lyons and seriously injuring photojournalist Jesse Walden, before going to a nearby residence where he allegedly killed 9-year-old T'yonna Major and injured a woman she was with.

It is the charges in those cases that will soon be filed, Mina said.

The two afternoon shootings happened minutes apart, but Mina said it is not yet clear which happened first.

"We’re looking at video and talking to witnesses, trying to figure all that out," he said.

Mina said evidence currently indicates that Walden was shot outside his news car, while Lyons was shot while sitting inside it. 

"I’ve been doing this for 32 years," Mina said. "I’ve never, ever seen a case where the suspect returned to the scene armed with a handgun and start shooting again. It just doesn’t happen."

Authorities arrested Moses around 4:30 p.m. Wednesday, and Mina said the 19-year-old has not been cooperating with the investigation so investigators have not been able to determine if he actually knew any of the victims.

"Our focus now is on providing the best case possible and tying up every single loose end, collecting all the evidence we can," Mina said.

Mina said he expects the two additional murder charges, along with other charges related to the shootings, early next week.