Updated at 4:49 p.m. ET

On what would have been Ahmaud Arbery's 26th birthday, Georgia state authorities said Friday that more arrests are possible in the shooting death of the black jogger who was killed while unarmed in February in the Satilla Shores neighborhood in Glynn County, Ga.

The director of the Georgia Bureau of Investigation, Vic Reynolds, also shed light on his department's swift decision to arrest two white men, a father and son, in connection with Arbery's killing, two days after taking over the investigation from local authorities.

On Thursday, Gregory McMichael, 64, and his son Travis, 34, were charged with murder and aggravated assault. The McMichaels are being held in the Glynn County Jail, according to a GBI press release. Gregory McMichael is a former investigator with a local district attorney's office.

When asked about additional arrests, Reynolds replied, "Don't know yet. We're going to go wherever the evidence takes us."

Cellphone video posted online earlier this week, which appeared to capture Arbery's Feb. 23 death, sparked national outcry and calls for arrests.

"We're investigating everyone involved in the case, including the individual who shot the video," Reynolds said.

President Trump weighs in

In a phone interview with Fox News on Friday, President Trump was asked about that case, which he called a "very sad thing."

"It's a very disturbing situation to me, and I just, you know, my heart goes out to the parents and the family and the friends," Trump said.

"To anybody that watched it, certainly it was a disturbing or troubling video, no question about that," he said, adding: "It's a sad thing, very sad thing. Hate to see that."

The Thursday evening arrests of the McMichaels, who have said they were acting in self-defense, caps off several days of rapid developments in the Arbery case. It had stalled for more than two months with no charges filed. Two district attorneys had recused themselves from the case.

On May 5, after the video was released, Atlantic Judicial Circuit District Attorney Tom Durden requested GBI investigate the Arbery death. The local police department also asked for assistance from state authorities.

Reynolds said during the press conference that agents pored over the investigative file compiled by the local authorities most of the day on Wednesday. By about 5 p.m. Thursday, Reynolds said his agents "had established sufficient probable cause to seek arrest warrants" against the McMichaels.

When asked what his department saw in the case file that local authorities might have missed, Reynolds said, "I can't answer what another agency did or didn't see."

"But I can tell you that based on our involvement in this case, considering the fact that we hit the ground running Wednesday morning, within 36 hours, we had secured warrants for two individuals for felony murder. I think that speaks volumes for itself and that the probable cause was clear to our agents pretty quickly."

Following the McMichaels' arrests Thursday, family attorney Benjamin Crump tweeted, "it took 74 days but Ahmaud Arbery's killers have finally been arrested!"

Facts of the Arbery case

Gregory McMichael told police that there had been several recent break-ins in the neighborhood and that while in his front yard, he saw the person he suspected from those incidents "hauling ass" down Satilla Drive toward Burford Drive, according to a Feb. 23 Glynn County Police Department incident report.

The McMichaels hopped in a truck with guns, the older McMichael with a .357 Magnum and Travis a shotgun, the report states. When they eventually caught up to Arbery, the younger McMichael exited the truck with his shotgun, and that's when the "unidentified male began to violently attack Travis" and the two men began fighting over the gun, the McMichael's statement to police said.

Travis McMichael shot twice, the police report states.

The facts of what is publicly known about the case are somewhat clear, Georgia Public Broadcasting's Emily Jones said Friday on Morning Edition.

"As for why this may have taken so long, Gregory McMichael has worked in law enforcement in the area for more than 20 years, including time working as an investigator in the district attorney's office in Brunswick," Jones said.

Arbery's family has characterized his death as a modern-day lynching. His aunt, Thea Brooks, told GPB News that even though the community is celebrating the arrests, there is a long way to go before the case is resolved.

"This is only the beginning," she said. "We still gotta wait for the conviction. This is just the start."

There will be no hate crime charges

NAACP President Derrick Johnson said during a Friday afternoon media briefing that the Arbery shooting represents just the latest in an "ongoing, systemic attack on African Americans" by law enforcement and vigilantes.

"The sad part of this," Johnson said, "is these attackers felt that they were within their right of white privilege and protected by the color of law because one of them happened to be a former law enforcement officer."

At the press conference, Reynolds, the GBI director, was asked whether there was enough evidence to charge the McMichaels with a hate crime.

"There is no hate crime in Georgia," Reynolds said.

Georgia is one of four states, along with Wyoming, Arkansas and South Carolina, that don't have hate crime laws on the books and don't require officials collect data on hate crimes, according to the U.S. Department of Justice.

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