A Dallas Methodist minister who refused to talk to police investigating an attack on his wife was subpoenaed Thursday to appear before a grand jury, his attorney said.

The subpoena orders the Rev. Walker Railey to appear before the panel July 29, said lawyer Doug Mulder.

On Wednesday, Mulder said his client would be willing to appear before the grand jury, but the Dallas County district attorney's office decided to issue the subpoena anyway.

Police have said the former minister at the First United Methodist Church of Dallas has not cooperated fully with the investigation into the attack on Margaret (Peggy) Railey. She was found choked almost to death April 22 in the family's garage and remains in a coma at a nursing home.

Detectives say their investigation is at a virtual standstill because the minister has refused to be interviewed for 10 weeks.

On Mulder's advice, Walker Railey has declined to answer questions, investigators say.

On Tuesday, prosecutor Norman Kinne said he planned to call Railey before a grand jury to clear up what he called inconsistencies in the minister's account of his activities on the night of the attack.

Mulder said the subpoena was unnecessary and that his client would appear before the grand jury at any time. "I have not withheld my client from the police," he said. "I don't think it's in our best interest" not to cooperate with investigators.

Railey, 40, has said he was working late the night of April 21 at libraries on the Southern Methodist University campus and returned to find his wife near death.

Eight days after the attack -- the morning police wanted to question him -- Railey took an overdose of pills, officials said. A note he reportedly left said he felt besieged by demons.