BELTON, Texas (AP) Seven months after a Fort Hood soldier was found stabbed to death in his apartment, a third person has been charged in his murder his ex-girlfriend who started receiving $100,000 from his life insurance policy after he died.

Kathryn Nellie Briggs, 27, of Austin, was charged with capital murder and remained in the Bell County Jail on $750,000 bond Thursday. She was indicted last week after authorities issued a search warrant for her Austin home and removed some items, but her name and information were withheld at the time, the Killeen Daily Herald reported.

Staff Sgt. Ryan Michael Sullivan was found dead Oct. 14 in his off-post apartment in Killeen after officials from his unit were worried when he did not show up for physical training. Sullivan died from repeated stab wounds from a sharp object, according to an autopsy report.

Briggs, who began receiving proceeds from Sullivan's life insurance policy on Oct. 31, had less than $5 in her bank account right before he died, according to an affidavit.

In the hours surrounding Sullivan's murder, Briggs exchanged numerous phone calls and text messages with soldier John Anthony Valdez Jr., 24, according to the document.

A week after Valdez was arrested in November in connection with Sullivan's murder, Briggs started depositing money into his jail bank account. Over the next six months Briggs also talked to Valdez repeatedly while he was in jail, discussing gathering funds for his bond, the need to get him out of jail quickly and claims that the police had no hard evidence, according to the affidavit.

But in an effort to hide Briggs' involvement, Valdez previously bought a cell phone in a fictitious woman's name, according to the affidavit. Valdez has made calls from jail to that number, and investigators believe that woman is really Briggs disguising her voice because they have been unable to find the other woman. That name is listed as a potential jail visitor for Valdez, although she has never visited, the Temple Daily Telegram reported.

In January another soldier, Kyle James Moesch, 23, was arrested on a charge of tampering with evidence in the Sullivan case.

Valdez and Moesch were indicted in February on capital murder charges in connection with Sullivan's death.

Moesch told police he was staying at Sullivan's home on Oct. 10, awoke during the night and found him dead. Valdez was standing near the body wearing a ski mask, and when Moesch asked if he killed Sullivan, Valdez kicked Sullivan's limp feet and said, "Yes," according to the affidavit.

Moesch told police that he left Fort Hood and met Valdez on Oct. 11, and then they went to Austin and disposed of bloody clothes in a trash bin.

Copyright 2009 The Associated Press.