Marine Clinging to Life After Shooting : Crime: She and a co-worker were shot on the El Toro base. The FBI says her ex-boyfriend, who’ll be arraigned on attempted murder charges, stalked her for six years.

A Marine remained in critical condition Saturday as FBI officials prepared to file charges against her former boyfriend who allegedly opened fire on her and a co-worker while they were on duty at the El Toro Marine Corps Air Station.

Staff Sgt. Deborah L. House, 31, was still clinging to life at the intensive care unit of Western Medical Center-Santa Ana, a hospital spokesman said. The second shooting victim, Cpl. Patrick D. Crudup, 20, was listed in stable condition.

FBI officials said 30-year-old Aldaten L. Bush, the suspect in Friday’s shooting inside the Marine compound, was being held at the Metropolitan Detention Center in Los Angeles. Bush, an ex-Marine from South Carolina, will be arraigned Monday on attempted murder charges in federal court in Santa Ana.

Jim Donckels, senior agent with the FBI in Santa Ana, said Bush had threatened and stalked House for six years. Bush and House have an 8-year-old son together, but separated six years ago after Bush put a gun to her stomach and threatened to kill her, Donckels said.

On Friday, Bush acted on his threats when he slipped into the El Toro base about 10 a.m., Donckels said. Bush was dressed in battle fatigues and was armed with a 9-millimeter semiautomatic pistol. As a veteran, Bush could show identification and be allowed on base. But he concealed the gun against regulations, base officials said.

After entering the base, Bush drove to a squadron building where House worked, chased her into a women’s bathroom and shot her in the head. Crudup and another Marine who worked with House heard her screams and ran to help. But Crudup was also shot in the head while his colleague managed to escape through the bathroom window.

Military police found Bush a short distance away and arrested him.

It is not known how House and Bush met, but Donckels said she apparently left him sometime after he pointed a gun at her in 1986 while she was stationed at the Twentynine Palms Marine Air-Ground Combat Center.

From his home in South Carolina, Bush had called House, threatening her and demanding to see his son, Donckels said.

House was transferred to El Toro in November, 1989. She remarried and lived with her husband, her son by Bush, a daughter and her husband’s son.

Bush told acquaintances at El Toro that he would one day take his son away and that if anyone got in his way, “he was going to deal with them,” according to an affidavit read by Donckels.

Base officials said Bush is also suspected of making a bomb threat received by a chaplain 10 minutes before the shooting, prompting military police to close all entrances and exits to the base.