DALLAS -- The family of Margaret Railey has filed suit against her husband, former United Methodist minister Walker Railey, accusing him of the attack in their Dallas home last April that has left her comatose.

A lawsuit filed by Billie Jo Nicolai, Margaret (Peggy) Railey's mother and legal guardian, is seeking damages for medical bills, mental anguish and the loss of enjoyment of her children, family and friends.

The civil suit could open new legal avenues for criminal prosecution in the case, according to attorney Bill Arnold, who is representing Nicolai free of charge.

"If, through discovery, facts come out that would help law enforcement, we're duty-bound to communicate those facts. But that's not the purpose of the suit," Arnold told the Dallas Morning News.

Walker Railey, formerly senior pastor of the 6,000-member First United Methodist Church of Dallas, had been regarded as a rising young star in his church. He has said he was not involved in the near-fatal attack on his wife in their home April 22 and said he was studying in the Southern Methodist University library when the assault occurred.

In the bizarre aftermath of the tragedy, Walker Railey, after recovering from an overdose of sleeping pills, took the Fifth Amendment 43 times before the grand jury investigating the case. He subsequently surrendered his ministerial credentials, gave temporary custody of the couple's two young children to a church colleague in Dallas and left the state.

The suit alleges that on the night of the attack, "Before going to the library and while Mrs. Railey was at home faithfully taking care of her duties as wife and mother, Mr. Railey went to visit his lover, Ms. Lucy Papillon, who lives near the SMU campus."

Papillon, a Dallas psychologist who is the daughter of a United Methodist bishop, testified earlier before a grand jury that she and Railey had dated for more than a year.

Ted Nicolai, Margaret Railey's younger brother, told the Morning News that while the family has remained silent until now, "The silence has never been easy. We were trying to keep all our thoughts focused on Peg and . . . how we could help her, not on his affairs. Now it's time for us to tell our side."

"I don't want him to be able to turn his back on what's happened," one family member told the Morning News. "I'd like for him, if he will not willingly accept responsibility, to be forced to accept some responsibility."

The article noted that unlike criminal proceedings -- in which proof beyond a reasonable doubt is required to convict a suspect of a crime -- civil suits require only a preponderance of credible evidence for a defendant to be held liable for damages.

In a civil case, unlike in a criminal trial, a defendant's refusal to testify may be used as evidence against him.

Rick Silva, the head of the Dallas police investigaton in the case, said he would "cooperate with whatever I can" in the civil suit.