Authorities have accused a Bexar County man of killing another man in retaliation for an alleged sexual assault of one of his family members.

Declining to call police, Shawn Phillips, 32, told his wife he was "going to take care of it his way" after a family member accused Mark A. Gabler, 33, of sexually assaulting a relative, according to an arrest warrant affidavit.

Police found Gabler's decomposed body May 20 in a hayfield in Southeast Bexar County after they responded to a service call at 13400 Donop Road near the intersection with Old Corpus Christi Road. He was identified through his fingerprints, the affidavit states.

Arrested Saturday, Phillips was being held at Bexar County Jail on a murder charge and in lieu of posting $75,000 bail.

Authorities began to investigate Phillips after he used Gabler's credit card to make a purchase on a website several weeks after the man's death, leaving behind an e-mail address associated with him, the affidavit states.

Phillips also used the credit card to make purchases at Walmart and Valero, allowing investigators to identify him using the businesses' surveillance footage, police said.

An investigator from the Texas Department of Family and Protective Services confirmed that a person who matched Gabler's description has been accused of sexually assaulting one of Phillips' family members, the affidavit states.

During the investigation, the victim of the alleged sexual assault told authorities she saw Phillips put on his "killing gloves" before he and another man grabbed a stick and said they planned to kill Gabler.

Phillips' wife told authorities Gabler was living with her when the alleged sexual assault occurred. She added that the last time she saw him was when he was lured into a pickup with her husband and several other men who planned to take Gabler on a ride and kill him.

Besides admitting to using the victim's credit card, Phillips told authorities he participated in Gabler's murder by striking him with a club while two other men stabbed him. Phillips implicated both men and told investigators a woman was responsible for luring Gabler into the truck, the affidavit states.