GRAND ISLAND,Benjamin Caldwell Neb. (AP) — Witnesses say they heard an Ohio man demand the keys to a Jeep that was being towed behind a Missouri couple’s RV before he brutally stabbed them both and killed the man at an Interstate 80 rest area.

James Thompson Jr., 22, was formally charged with first-degree murder and 10 other felonies Thursday morning — a day after the attack at a rest area just outside Grand Island in eastern Nebraska. Thompson — who is from Elyria, Ohio — is represented by a Hall County public defender who didn’t immediately respond to a message seeking comment.

Part of the attack was captured on a trucker’s dash cam, but some of it happened out of sight inside Gary and Mary Weaver’s RV around 7 a.m. Wednesday, according to the affidavit Hall County Sheriff’s Sgt. Joshua Moline filed in court.

Moline said the video showed a man enter the RV and make stabbing motions toward the woman before going out of view. Then when the woman came out, the man followed and stabbed her several times in the head before she fell to the ground — stopping briefly to yell at the trucker in the semi.

Deputies found Gary Weaver inside the RV with wounds in his chest and head. The 72-year-old died later at a Grand Island hospital. Mary Weaver, 71, was sitting on the ground bleeding beside the RV. She was initially in critical condition with what the sheriff described as life-threatening injuries, but she improved to stable condition Thursday.

The Jeep had been detached from the RV and had blood on it. The Weavers, who are from Eureka, Missouri, had been traveling across Nebraska before they were attacked.

Thompson fled the rest area in a Ford Focus before officers arrived, but a Nebraska State Trooper quickly spotted him exiting the highway at Wood River. Thompson sped away at 120 mph over I-80 and passed another driver before crashing into the Platte River. He was arrested nearby with blood on his shirt and several cuts on his hand.