A massive manhunt was underway across at least two states after a shooting rampage at a Maryland granite supplier left three people dead and two others critically wounded, authorities said. The suspect used to live in Washington state.

Harford County Sheriff Jeffrey Gahler said Radee Labeeb Prince is accused of opening fire at Advanced Granite Solutions in Edgewood, 25 miles northeast of Baltimore.

Gahler said Prince and all the victims were employees of the company. Prince, 37, worked at the company for about four months and was scheduled to work Wednesday, Gahler said.

He urged Prince to turn himself in and "end this peacefully" before more lives were lost.

"This does appear to be a targeted attack for that business," Gahler said, adding, "There is an armed and dangerous suspect out there."

Gahler said authorities arrived on the scene four minutes after the first call. He said there were "quite a few more than five" employees at the company when the shooting began, and he believes Prince would have killed more employees if he had the chance.

Police in Wilmington, Del., said they were also looking for Prince in connection with a shooting a short time after the Maryland attack. No details were immediately released. Police said in a statement that Prince lived in Wilmington, about 50 miles northeast of Edgewood.

Authorities were searching for a 2008 black GMC Acadia with Delaware license plates. Maryland Gov. Larry Hogan said state police were working with federal and local authorities to track Prince.

"State helicopters are in the air and state troopers are on the ground from multiple barracks," Hogan said. "I ask all citizens — especially those in this area — to please remain vigilant."

An online database shows Prince had a Des Moines, Wash., address in late 2013 and a Renton address in late 2008 to early 2009. He had two warrants out for his arrest -- one for a hit and run in 2014 and one for failing to renew expired license plates.

Gahler said the suspect had a criminal record but did not go into detail. Harford County Public Schools locked down five nearby schools as a precaution.

Gahler said Prince used a handgun and apparently acted alone. He said it was too soon to determine a motive and employees of the company were speaking to investigators.

The tragedy was the second deadly shooting attack this year in the suburban county of 250,000. In February, two county sheriff's deputies were fatally shot at a shopping center by a man who was killed by authorities at the scene.

"Once again we find ourselves dealing with a shooting incident here in Harford County, "Gahler said. "Our thoughts and prayers go to the... families that we know all too well are going to be forever impacted."