Authorities are starting the process needed to bring back to Arkansas a man accused of killing his mother-in-law and her parents in Lee County, state police said Wednesday.

Gordon Randal Gwathney, 46, of Marianna was arrested at 7:30 p.m. Tuesday in front of a McDonald's restaurant in Laredo, Texas, Arkansas State Police spokesman Bill Sadler said.

"The individual was armed, but he did not resist," Sadler said.

Formal charges were pending in Lee County.

Sadler said the Arkansas State Police were working with the Laredo police and Webb County, Texas, authorities to transport Gwathney to Arkansas to face charges.

Officials said Tuesday that Gwathney was headed for the border with Mexico.

Police began searching for Gwathney after the shootings early Tuesday just south of Palestine in eastern Arkansas. Officers said Gwathney shot his estranged wife's mother and grandparents at their rural Arkansas home, then wounded his brother-in-law and a sheriff's deputy.

Gwathney was believed armed with a rifle and possibly other weapons when he drove away in a pickup truck from the Lee County residence, Arkansas State Police Major Cleve Barfield said.

Sadler had no information on whether Gwathney was armed when he was taken into custody at Laredo.

Gwathney has a military background and is familiar with firearms, Barfield said at a news conference where authorities asked for the public's help in finding the suspect.

The St. Francis County sheriff's office received a 911 call about 1:45 a.m. to a home off Arkansas 261 about five miles south of Palestine in Lee County, where Gwathney's wife Lisa Gwathney was living. The St. Francis County sheriff's office is closer to the home than Lee County's.

St. Francis County Sheriff Bobby May said Gwathney and his wife Lisa are going through a divorce and that Lisa Gwathney had moved into the home where her mother and grandparents lived. "They have been separated for a while and she had filed for divorce. Apparently, that's what initiated this whole situation," May said.

The sheriff said Lisa Gwathney, 35, heard the shootings and was able to get out of the house through a window and run for help. Her mother, Sylvia Reeves, 51, was killed, along with her grandparents' J.O. Mitchell, 81, and Evelyn Mitchell, 79.

Outside, Lisa Gwathney's brother, Travis Reeves, who lives nearby, got into a gunfight with Gwathney and was wounded, Sadler said earlier in the day. Deputy Tracy Jackson, dispatched to the residence, was injured as Gwathney fired at his truck, shooting out his windows, May said.

"He's one lucky boy. I don't see how he avoided getting killed," May told the Times-Herald newspaper of Forrest City. "He spent most of this morning at the hospital getting sewn up and getting glass pulled out of his face and body."

Sadler said Reeves was admitted to a hospital in Memphis, Tenn.