They’d been married for 30 years and seemed to have the perfect life, but when BECKY BRYAN’s husband was allegedly gunned down by a stranger in their living room, right in front of her, she laughed as investiga­tors collected evidence!

Becky and her husband Keith, who served as the chief of the Nichols Hill Fire Department in Okla­homa, had two grown sons and two young grandchildren, and they owned a beau­tiful house in the nearby town of Mustang.

Jim McNabb, the pastor at the Bridge Assembly of God in Mustang, said the couple was active in the church, taught Sunday school and sang in the choir –but behind the scenes, all was not well in their marriage.

IN December 2009, Becky began having an affair with a married man named Mark Holbrook, a client at her real estate office. He broke it off after a month. “I began to realize she wasn’t the person I thought she was,” he said.

Holbrook called Keith to apologize. Incredibly, Keith forgave him – but Becky blew up! According to Hol­brook, she called his wife, his parents and his son, trying to “stir things up.” Cops say she also called Holbrook and left a voice message boasting that she stood to inherit a lot of money.

Three hours later, at 10 p.m. on Sept. 20, 2010, Becky called 911 to say Keith had been shot.

Officers found the fire chief still breathing, but barely alive with a gun­shot wound to the head. He died at the hospital the following morning.

“Mrs. Bryan claimed an intruder got into the house through the garage and shot her husband one time in the head and fled out the garage,” Ca­nadian County Assistant Dis­trict Attorney Paul Hesse told The ENQUIRER.

Becky added that the hooded intruder told her: “Ma’am, I’m sorry, but your husband should have hired me.”

Cops searched the house and they found the murder weapon, a Ruger LCP 380 pistol, along with a spent shell casing and a latex glove in the clothes dryer.

“Had the shooter gone out of the house the way she said he did, he would not have passed the utility room where the dryer was,” Hesse noted.

Mustang police Detec­tive Camie McNeil added that Becky started laughing as her hands were being swabbed for gunpowder residue.

“She said she watches ‘CSI’ and knows all about this stuff,” McNeil recalled. “Her behavior was uncharacter­istic of a woman seeing her husband being gunned down.”

And that wasn’t her only bizarre be­havior. A friend of Becky’s revealed that as they were driving to the hospital to see Keith, Becky showed her a photo­graph of a man’s private parts and said she’d had sex with him earlier that day.

Just three days after the shooting, Becky was arrested and charged with first-degree murder. She’s facing life in prison without parole if convicted.