A federal grand jury indicted a Texas businessman today in the Florida slaying of his ex-wife, a mother of quadruplets.

Allen Blackthorne was arrested after playing golf in San Antonio, said his lawyer, Richard Lubin of West Palm Beach, Fla. The indictment remained sealed tonight.

Lubin said he was unaware of the specific charge against his client, but KMOL-TV reported Blackthorne was charged with conspiracy to commit interstate family violence.

"We, of course, for two years have been offering to turn him in if they ever decided to charge him," Lubin said in a phone interview. "We again made that offer in writing today, but they chose to arrest him rather than voluntarily surrender."

Lubin said Blackthorne is looking forward to the opportunity to prove his innocence.

"This is a terrible tragedy what happened here, but Allen Blackthorne had nothing to do with it," he said.

Federal and state authorities have been investigating the Nov. 7, 1997, death of his ex-wife, Sheila Bellush, 35, who was shot and stabbed in her Sarasota, Fla., home.

Her 2-year-old quadruplets were found wandering in blood near her body. The children were not physically harmed.

The U.S. attorney would not comment and the district attorney did not return a phone message. They planned a joint news conference Wednesday.

Bellush's killing occurred six weeks after she and her husband, James Bellush, and children moved to Florida from San Antonio. She had two older daughters in addition to the quadruplets.

Two men are serving prison sentences in connection with the scheme to kill or maim Bellush. Another, alleged triggerman Jose Luis Del Toro, is awaiting trial.