Formal charges of murder and attempted murder were filed Thursday morning against Gregory Ulrich, the suspected gunman in the deadly shooting Tuesday at an Allina clinic in Buffalo.

Investigators say Ulrich, 67, of Buffalo, set off two homemade bombs in the clinic and shot five people, leaving four seriously injured and one dead. The violence occurred in the span of about 6 minutes before officers arrived and found him lying face down amid the destruction, CBS reports.

“Gregory Ulrich went to Allina clinic knowing that he was going to shoot up that clinic. Gregory Ulrich went to that clinic knowing he that was going explode bombs at the clinic. He did just that, cowardly injuring innocent people, one of them fatally,” Wright County Attorney Brian Lutes said during a morning news conference.

Ulrich is charged with one count of second-degree intentional murder, four counts of first-degree premeditated attempted murder, one count of discharging an explosive device, and one count of carrying a pistol without a permit in a public place.