Authorities have identified the man behind Thursday afternoon's shooting at Sioux Steel in Lennox as Jeffrey DeZeeuw.

The 51-year-old Sioux Falls man was found next to a burned out Plains Xpress semi-trailer on a gravel road about three miles south of Lennox hours after the shooting.

Lincoln County Sheriff Dennis Johnson said DeZeeuw shot and killed Jon Richter, 45, following a workplace dispute at Sioux Steel's ProTec facility.

Also shot in the incident was Kathy Steever, 46, of Lennox, a friend and coworker of the Richter. Steever was taken to the hospital, where doctor are treating her for her injuries.

"She actually has improved this morning," said Lennox Police Chief Orville Jorgensen.

Authorities say DeZeeuw, who was a contractor for a company that worked with Sioux Steel, entered the building around 9:30 a.m. Thursday morning and got into an argument with Richter.

DeZeeuw left soon after, Johnson said.

"He came back shortly before 2 p.m. and shot and killed Mr. Richter, then shot and injured Ms. Steever," Johnson said. "(DeZeeuw), at a minimum, was targeting (Richter)."

At that point, Brian Roesler, 45, came from another part of the building and confronted DeZeeuw. The men fought over the handgun, but was unable to get the gun away.

"We believe he was struck over the head several times by the suspect and that how he was injured," Johnson said.

After the fight with Roseler, DeZeeuw left the building, Johnson said.

Authorities found DeZeeuw's body after extinguishing the trailer that was found fire south of town. They used dental records to identify him. A handgun believed to have been used during the shooting was also found in the burned out semi.

Sheriff Dennis Johnson said DeZeeuw committed suicide following the shooting.

A search warrant was served on DeZeeuw's home and a sport utility vehicle, but nothing turned up related to the shooting.

Jorgensen credited Rosler Friday morning with bringing about "the best possible resolution to a senseless, horrifying incident."