NEW YORK (AP) _ Isabella Rossellini, actress daughter of the late Ingrid Bergman, testified that her twin sister's ex-husband once threatened to kill his son and then himself.

The crisis arose years ago when her sister, Ingrid Rossellini Aborn, allowed her ex-husband to have an unsupervised visit with their little son Tommaso, Ms. Rossellini testified Tuesday in Alberto Acciarito's harassment trial.

After that visit, a screaming and cursing Acciarito telephoned the actress from a hotel and ``said he would throw the child out of the window and then commit suicide,'' the actress-model testified.

``I signaled my husband to call police and I tried to keep him on the phone so he would not jump out of the window,'' Ms. Rossellini testified. She said a friend went with police to pick up the boy, who in 1986 was almost 7.

Acciarito, 44, a film director and producer who lives in Rome, is charged with aggravated harassment and three lesser charges for allegedly calling and threatening his former wife.

Acciarito's lawyer, Carol Zimmerman, said he merely tried to overcome the obstacles Mrs. Aborn erected to keep him from a relationship with their son, now 18.