US Police alleged Chansamorn Pokai and her friend Stephen Brockway hired Ronald Rosser to murder Richard Moore, 66. The victim's body was found riddled with gunshot wounds in his house.
The US media quoted police as saying that the couple had an unhealthy relationship, and that officers had been to their home as recently as January to hear complaints that each had been unfaithful.
"This was not a healthy relationship," assistant McKinney Police chief Randy Roland said.
Investigators had called on the couple's home several times in recent months.
"The last call we had was in January, I believe, of this year, and it was regarding infidelity. We uncovered that both sides accused each other of being unfaithful."
Police said Chansamorn initially reported finding her husband alone in their home with multiple gunshot wounds, though detectives were later able to piece together facts that the woman and Brockway hired Rosser to kill Moore and that the motive was money and marital problems.
"Part of our ongoing investigation is to find out if there is a romantic relationship [between Chansamorn and Brockway], how involved they are and when did that friendship start," Roland said.
McKinney police yesterday with the help of East Texas police departments and Texas Rangers arrested Ronald Rosser. Also yesterday, the McKinney Police Department and Texas Rangers arrested Chansamorn and Brockway.
Rosser is being held on unrelated federal firearms and capital murder charges at the Gregg County Sheriff's Office. Chansamorn and Brockway are being held in the Colin County Jail.
All three suspects are charged with capital murder, and each is held on a US$1 million (S$1.38 million) bond.