TYLER, Texas - A man angry about being sued for unpaid child support opened fire with an AK-47 assault rifle outside a courthouse, killing his ex-wife and a man trying to help the couple's adult son.

The gunman, 43-year-old David Hernandez Arroyo Sr., was killed Thursday afternoon in a gun battle with officers a few miles away after wounding his son and three law enforcement officers.

Police said Arroyo, who had a history of spousal abuse and weapons violations, shot 50 rounds in the historic town square. He was wearing a military flak jacket and bulletproof vest.

"He definitely came well-armed and prepared," police Chief Gary Swindle said. "We do understand there had been some threats made by him the previous week."

But the attorney representing Maribel Estrada, 41, said he doesn't believe she thought her ex-husband was dangerous. Estrada worked at a meat packing plant in Tyler and raised a 17-year-old and a 6-year-old with the help of her eldest son, Joshua Wintters said.

The other victim, Mark Alan Wilson, 52, was credited with saving the life of David Hernandez Arroyo Jr., who was listed in fair condition at a hospital with leg wounds. A sheriff's deputy, Sherman Dollison, 28, was in critical condition after being shot in the liver, lungs and legs; a sheriff's lieutenant and a Tyler police detective were treated and released.

Wilson, a gun enthusiast who once owned a shooting range, intervened after Arroyo killed his ex-wife, witnesses said. Swindle said Wilson shot at Arroyo several times but his rounds weren't penetrating the armor.

"They traded shots, missing each other, and then the gunman hit Wilson and Wilson went down," Tyler Morning Telegraph publisher Nelson Clyde III said in today's editions of the newspaper. Clyde watched the shooting from a nearby restaurant.