A Fairfax County man has been charged with killing his wife in 2017, following an extensive, two-year investigation, police announced Friday.

Laszlo Pentek, 55, was arrested by a Fairfax County police SWAT team outside his home in the Mantua area on Friday afternoon, police said. Pentek has been charged with murder and use of a firearm in the commission of a felony in connection with the slaying of Donna Pentek, 51.

Fairfax County police officers were called to the family’s single family home in the 9200 block of Okla Drive on the afternoon of Jan. 6, 2017, after a family member came home and discovered Donna Pentek shot, said Fairfax County police Major Ed O’Carroll at a news conference.

Donna Pentek was pronounced dead on the scene and Laszlo Pentek was taken to the hospital with a gunshot wound, O’Carroll said. Police officials declined to say how Laszlo Pentek was shot.

O’Carroll said there was no sign of forced entry on the house, and from early on police called the incident a domestic-related shooting. No motive was given for the slaying, and O’Carroll declined to release other details about the incident, since a trial is still pending.

O’Carroll did not specify why police spent two years investigating the case, but said it involved forensic work.

“These cases are not easy to work,” O’Carroll said. “Sometimes complex cases do take time to work.”

Neighbors said the Penteks had two children. The family had lived in the home for at least a decade before the killing.