A multi-state manhunt was underway Wednesday for a man suspected in a workplace shooting in Harford County, MD, that killed three people and critically injured two others, and who is believed to have later shot another person in Delaware.

State and federal authorities are searching for Radee L. Prince, 37, who they believe shot five people around 9 a.m. at a kitchen countertop company in an Edgewood business park where he had worked for the past four months. The five victims were all employees of the business, Advanced Granite Solutions.

"This does appear to be a targeted attack, limited to that business," Harford County Sheriff Jeffrey Gahler said at a morning news conference.

Later in the day, however, police in Wilmington, DE, said Prince was also being sought in connection with a shooting that occurred almost two hours later, at around 10:45 a.m., at a used car dealership.

Prince is believed to be traveling in a black 2008 GMC Acadia with Delaware tags. Authorities said he is considered armed and dangerous, and urged anyone who believes they see him to use “extreme caution.” The FBI and ATF were both involved in the search and Prince’s information was put on highway billboards from Philadelphia to Washington DC and from Atlantic City to Salisbury, the Baltimore Sun reports.

Prince had several prior arrests and run-ins with law enforcement, court records show, including gun charges and a restraining order.