LOS ANGELES>> Charlie Sheen’s wife claimed this week that the TV star threatened to stab her in the eye. She also said he vowed to decapitate her and send her severed head to her mother.

Brooke Mueller’s statements were enough for a Los Angeles judge to issue a temporary restraining order against Sheen, who has already been convicted twice for domestic violence.

But the statements were not enough for the Los Angeles Police Department to open a criminal investigation. LAPD officials said they’ve discussed the issue and determined that they can only launch a probe if Mueller files a complaint, which as of Friday she has not.

"It is incumbent on her to come forward and make a police report," said Los Angeles Police Sgt. Mitzi Grasso. "Our hands are tied."

Those who help domestic violence victims said Sheen’s case is in many ways similar is to many others they see — women who get restraining orders but are too frightened or otherwise unwilling to report incidents to police. They say getting domestic abuse victims to make police reports is a continuing struggle. Victims sometimes fear reporting an abuser to police would lead to the abuse’s arrest and make life more difficult — financially or emotionally — for the children.

TuLynn Smylie, executive director of Women’s Shelter of Long Beach, Calif., she she believes police should investigate "if a judge believes there is enough evidence for a restraining order that says she has a credible story."

Smylie and others said the Sheen situation focused attention on the quandary for police. "If a police report isn’t made it makes it very hard for law enforcement," said Olivia Rodriguez, executive director of the Los Angeles County Domestic Violence Council. "When we get involved one of the first things we emphasize to survivors is to make a police report."

The restraining order issued by Los Angeles County Superior Court Judge Hank Goldberg on Tuesday came after Mueller, in the declaration, accused the actor of being "insane." Mueller alleged Sheen threatened to kill her repeatedly, including Sunday night when he allegedly told her, "I will cut your head off, put it in a box and send it to your mom!" In a text, she said, he talked about killing his manager.

Her attorney did not return calls seeking comment Friday. Sheen’s attorney declined to comment, but the actor has said he does not hit women.

Mueller and Sheen separated after a domestic violence incident in 2009 in Aspen, Colo. Sheen pleaded guilty to misdemeanor third-degree assault after the incident, in which Mueller told authorities he held her at knife point. In October 2009, she alleged in the declaration the actor "knocked me to the floor, causing me to hit my head on the corner of a couch. I was knocked unconscious and required medical attention, including a CAT scan."

The actor had previously pleaded no contest to a misdemeanor charge of battery with serious bodily injury for a 1996 incident where he was accused of knocking then-girlfriend Brittany Ashland to the floor.

Attorney Gloria Allred, who represented Ashland in 1996, said she was troubled to read about the allegations contained in Mueller’s restraining order application, saying some of the details are similar to earlier allegations made against Sheen.

Allred said that while its general police policy not to investigate domestic violence claims without a report, there is nothing legally stopping them from doing so if officials think the case is serious enough.

"Ultimately there is nothing to stop them pursuing it. If they are aware of a dangerous situation they should at the least ask her if she wants to fill a report," Allred said. "This is a public safety matter because could endanger others including the police officers who respond to a domestic violence call."

Allred also suggested another option for police: "They should go out and ask if she wants to file a police report."

In a CNN interview with Piers Morgan this week, Sheen said he is not a violent person.

"Women are not to be hit," He said."They are to be hugged and caressed."

But then Sheen did recall an incident where he claimed a woman attacked him and he had to "contain" her.