Authorities in Baton Rouge said Tuesday that they have arrested a white man in the fatal shooting of two black men in separate incidents last week. Police have described the shootings as potentially racially motivated.

On Tuesday, while announcing the arrest and charges, officials also said that the suspect may be linked to a third shooting last week, as well — this one targeting a home with black residents. Two people were inside, but they were unharmed, Hillar C. Moore III, the district attorney in East Baton Rouge, said at a news conference.

Moore said the man in custody — Kenneth James Gleason — is thought to have fired at the two men killed last week while inside his car before getting out, standing over them and firing additional shots.

“It appears to be cold, calculated, planned,” Moore said, adding that the attacks targeted ”people who were unarmed and defenseless.”

[Two apparently random shootings in Baton Rouge could be racially motivated, police say]

The Baton Rouge police chief said Tuesday that Gleason’s arrest in the “brutal murders” last week probably  saved lives because the 23-year-old “would’ve probably killed again.”

Gleason — who had been arrested, released and rearrested during the investigation — could face the death penalty, Moore said.

Although officials have not definitively announced a motive, citing the ongoing investigation, they said earlier that the two killings could have been racially motivated. Gleason has spoken to authorities, Moore said, but the prosecutor declined to elaborate on what was said.

The first known fatal shooting occurred Tuesday, Sept. 12, when Bruce Cofield was killed, according to authorities. Cofield, a homeless man known to people in the community, was fatally shot late that night. Two days later, police say, Donald Smart was found with fatal gunshot wounds. Smart was a popular employee at Louie’s Cafe, a diner near the Louisiana State University campus.

A third shooting predated Cofield and Smart’s deaths, Moore said when outlining a timeline in the case at the news conference. On Monday, Sept. 11, Moore said, Gleason fired three shots from a 9mm gun at an occupied home not far from his own.

Gleason was booked Tuesday in the East Baton Rouge Parish Prison on counts of first-degree murder, illegal use of a weapon and aggravated criminal damage to property.

“He strongly denies the allegations, and he will be vindicated,” Chris Alexander, Gleason’s attorney, wrote in an email Tuesday.

The shootings come as racial tension has flared up across the country recently, erupting in violence in places such as New York, where a white man fatally stabbed a black man he encountered on the street; Portland, Ore., where two men were fatally stabbed while trying to intervene when a train passenger began shouting anti-Muslim hate speech; and Kansas, where a man was indicted on hate-crime charges in the fatal shooting of one Indian man and wounding of another.

Baton Rouge has also seen its share of violence and unrest, with an increasing number of homicides this year. Last year, the city was also the site of heated protests after police fatally shot Alton Sterling, a black man, outside a grocery store; two weeks later, three officers were gunned down in an ambush attack.

“Baton Rouge has been through a lot of turmoil in the last year,” Jonathan Dunnam, the interim police chief, said at the briefing. “Had there not been a swift conclusion to this case, I feel confident this killer would’ve probably killed again. He could’ve potentially created a tear in the fabric that holds this community together.”

Mayor-President Sharon Weston Broome (D) commended law enforcement officers for their work in the case.

“While the motive is still unclear, this person is off of our streets,” she said at the briefing.

[Fatal stabbing in New York was ‘practice’ for more attacks on black men, police say]

Officials cited a combination of evidence, help from members of the public, police work and technology in disclosing how they came to identify, arrest and charge Gleason. Moore said they were able to link Gleason to the shootings early Tuesday when DNA found on the shell casings matched his own.

Moore said Gleason bought a 9mm gun in Baton Rouge on Nov. 9. In July, Gleason bought a silencer that “thankfully” had not come yet, Moore said. The following month, Gleason completed a class to obtain a concealed-carry permit, although he did not get the permit yet either, Moore said.

Tuesday marked the third time in recent days that Gleason was booked into the prison, according to the sheriff’s office. He was booked on Saturday for purported drug possession and released on a $3,500 bond, prison records show. Moore said Gleason was arrested again Monday for allegedly stealing a copy of “The Hitchhiker’s Guide to the Galaxy,” the Douglas Adams sci-fi book.

That reported book theft factored into the timeline Moore offered Tuesday. The days when the shots were fired at the residence and Cofield was killed, police received reports about a white man with a red car spotted carrying a gun, Moore said. In one case, the man was seen putting the gun in bushes, but no gun was found, Moore said; in the other, the man was seen appearing to take off his license plate and putting a gun in the trunk.

On Tuesday, Sept. 12, the day Cofield was killed, “witnesses describe [seeing] a red car and a white male wearing tactical gear,” Moore said.

[Southern Poverty Law Center says American hate groups are on the rise]

The “Hitchhiker’s Guide” theft was reported the following day at a Books-a-Million in a mall in Baton Rouge. The report, given to police, described the potential suspect: a white man in a red car.

The next day, Smart was killed with 10 rounds fired from a 9mm gun, Moore said. Video was captured, but it was not helpful, Moore said. Two witnesses describe seeing something: a white man and a red car.

“Things are now starting to come together,” Moore said.

By Friday, shell casings picked up at the shooting scenes appeared to be the same caliber: 9mm. Moore said more common factors were seen potentially linking the fatal shootings.

“We have two African Americans that are killed, seem to be killed in the same matter, that is a red car that’s driving by, [someone] shoots from the car, then eventually after that person is taken down to the ground, then gets out of the car and apparently over the victim, if the victim is injured or dead, and continues to fire,” Moore said.

Investigators began searching for the red car, looking at footage appearing to show the vehicle as well as a white man taking a license plate off it. Moore said an officer working extra duty found the car on Saturday.

Search warrants were issued that day, while Gleason was booked on the drug charges and interviewed. He was released Sunday on bond and then rearrested Monday in the book theft, Moore said.

Early Tuesday, the DNA was found to be a match, Moore said, and Gleason was arrested again.

Further reading:

‘Shut up, slave!’: A spilled Starbucks drink leads to sidewalk fight — and hate-crime charges

‘Thank God you missed one’: Bodycam records cop mistakenly shooting photographer he knows