Death threats phoned in to a hotel where Catherine Zeta-Jones (search) was staying are linked to a woman accused of stalking and threatening the actress, a sheriff's detective testified Friday.

Detective Rodney Wagner said at a preliminary hearing that phone bills showed the calls were made by Dawnette Knight (search), 33, who is charged with one felony count of stalking and 24 felony counts of making criminal threats.

In two of the calls, made on May 18 and 19, the caller told a receptionist, "We know she is in the hotel. We are going to kill her," Wagner testified. The caller mentioned Michael Douglas (search), the actress' husband.

The detective said that in a third call, on May 21, the caller threatened to "blow Catherine's head off on Sunday in Monte Carlo."

Prosecutors are trying to show Knight threatened Zeta-Jones because she had a crush on Douglas.

Knight has pleaded not guilty and is in jail with bail set at $1 million. She was arrested June 3 at her Beverly Hills home.

The judge in the case said Friday that Knight is being monitored because an anonymous caller has phoned the jail, saying she may try to kill herself. Knight's attorney, Richard Herman, said she was on suicide watch and was being kept in "medieval conditions" because of the calls.

He said Knight was not suicidal.

In a ruling Wednesday, Knight was found competent to stand trial. Her case had been halted July 30 pending a psychiatric evaluation after she overdosed on barbiturates.