A man suspected in a workplace shooting in Harford County that killed three people and critically injured two others was in custody Wednesday night after a multi-state manhunt.

State and federal authorities located Radee L. Prince, 37, late Wednesday in Delaware, the Harford sheriff’s office confirmed.

The Bureau of Alcohol, Tobacco, Firearms and Explosives said the arrest occurred in Newark, Del., “without incident.”

Police said Prince’s vehicle was first spotted about 5:35 p.m. near a high school in Newark. After police surrounded the area and set up a perimeter, Prince was arrested by three ATF agents after a brief foot chase about 7:05 p.m., police said. No one was injured during the arrest.

Prince is believed to have shot five people about 9 a.m. Wednesday at a kitchen countertop company in an Edgewood business park where he had worked for the past four months, police said.

The five victims were all employees of the business, Advanced Granite Solutions.

Prince is also alleged to have shot another person in Delaware later in the morning.

The three victims killed in the Edgewood shooting were identified by the sheriff’s office late Wednesday as Bayarsaikhan Tudev, 53, of Virginia; Jose Hidalgo Romero, 34, of Aberdeen; and Enis Mrvoljak, 48, of Dundalk. The wounded victims were not identified.

Burak Caba, the owner of Advanced Granite Solutions, said Prince worked as a machine operator, and Tudev, Romero and Mrvoljak all worked as granite polishers.

Caba said Tudev, Romero and Mrvoljak were all “the nicest people.”

“They never even raised their voices to their co-workers,” he said. “They were peaceful, happy people.”

As the manhunt unfolded and police flooded the Interstate 95 corridor seeking the suspect, Harford County Sheriff Jeffrey Gahler said: “There’s an individual out there on the loose who’s committed one of the most heinous acts in our county; we certainly consider him armed and dangerous.” Gahler called the shooting "a targeted attack, limited to that business."

Later in the day, however, police in Wilmington, Del., said Prince was also being sought in connection with a shooting that occurred around 10:45 a.m. at a used-car dealership there.

A single victim was shot in the head but is expected to survive, Wilmington Police Chief Robert Tracy said. He said the victim was shot twice, but was alert and identified Prince as his attacker.

Tracy said that Prince had a prior history with the shooting victim and that the two men had a “beef.”

“Every one of the victims that this individual shot, the victim and the attacker knew each other,” Tracy said at a news conference. “This is targeted. This individual knew the people he wanted to go shoot. This was not a random act of violence.”

The two wounded victims from the Edgewood shooting were listed in critical condition at Maryland Shock Trauma Center as of Wednesday evening, a hospital spokeswoman said.

Advanced Granite Solutions said in a statement: “Words cannot express our feelings. We mourn the loss of our friends. … May God give our friends eternal rest and the families the strength to bear the great pain.”

For hours police had been seeking a black 2008 GMC Acadia with Delaware tags that they believed Prince was driving.

The FBI and ATF were both involved in the search. Authorities put Prince’s information on highway billboards from Atlantic City, N.J., and Philadelphia to Salisbury and Washington, D.C.

Tracy said he believed the gun used in the Wilmington shooting was the same weapon used in the Edgewood shooting.

After Prince’s arrest, the ATF said it had recovered a handgun that it is tracing to determine where it came from and whether it was the weapon used in both shootings. The federal agency said it deployed command staff, two violent crime units, and canines that can sniff out spent shell casings on the case.

Earlier this year, according to a peace order complaint filed in Harford County, Prince had been fired from a job at another granite company after allegedly attacking a co-worker.

Another co-worker applied for the peace order, writing that though Prince had not attacked him personally, “I do not want to wait until he will. … He can also do it to me.”

Authorities gave a Delaware address for Prince, who attended Newark High School and had 42 arrests with 15 felony convictions and four misdemeanor convictions in the state, according to police.

A residence in Cecil County also was searched as part of the investigation, Gahler said.

Gahler said the first call came into law enforcement at 8:58 a.m. to the business park in the 2100 block of Emmorton Park Drive, and deputies arrived four minutes later.

The Advanced Granite website says its showroom opens at 8 a.m. on weekdays.

Kevin Doyle, 47, who works as a maintenance technician for Thornhill Properties, was on a job nearby. He was outside getting more tools from his vehicle when he saw people running from the shooting scene.

“Three guys came running. They were terrified,” Doyle said. “You could tell this was something big. They were in shock. One of them was crying, ‘They're shot in the head, they're shot in the head.’

“I started to go down there to see if I could help, and one of them said, ‘Don't go down there, there's shooting.’ ”

Gahler said there were “quite a few more than” five people at Advanced Granite at the time of the shooting, and witnesses were being interviewed. “We do not believe that anybody else was involved in this incident,” he said.

Advanced Granite Solutions designs, manufactures and installs granite, marble and stone countertops and other surfaces in Maryland, Pennsylvania and Delaware, the company’s website says. Emmorton Business Park is just south of the Interstate 95 interchange with Route 24, parts of it visible from the highway.

Prince had several prior arrests and run-ins with law enforcement, court records show. He pleaded guilty to 15 counts of third-degree burglary in Delaware in 2003, among the more than 40 arrests that Tracy, the Wilmington chief, said were on his record. He was also charged with several handgun violations in Cecil County in March 2015, but those charges were later dropped.

Tracy declined to discuss the nature of the crimes Prince was accused of in other Delaware arrests.

On Wednesday, there was a heavy police presence in the Elkton neighborhood where Prince had a listed address.

Gov. Larry Hogan addressed the Harford shooting during a Board of Public Works meeting, after briefly leaving to get an update on the unfolding search for the shooter.

“The state is providing every possible assistance to the local government. My thoughts and prayers are with the people, the families of those who have lost their lives and been injured,” Hogan said.

In a statement, Harford County Executive Barry Glassman said: “Our sympathy and prayers are with the families of the lost and the injured employees in today’s horrible shooting. Harford’s allied emergency services are assisting the Harford County Sheriff’s Office and the impacted families. In addition, my administration’s Department of Emergency Services is assisting our local, state and federal partners in apprehending the suspect.”

Baltimore Sun Media Group reporters Ted Hendricks, Erika Butler, Alison Knezevich, Kevin Rector, Jessica Anderson and Christina Tkacik contributed to this article.