A D.C. Superior Court jury heard opening arguments yesterday in the insanity trial of a Northwest Washington man whose diary led to his conviction last February for the murder of a local prostitute.

The jury will decide whether Rufus E. Adams, 36, of 704 Third St. NW was legally insane in October 1980, when he killed 24-year-old Alfreda Garner, who lived at 1536 Independence Ave. SE.

Adams' lawyer, W. Gary Kohlman, told the jury his client was a "very severely mentally ill person." Kohlman said he would present evidence, including the testimony of a psychiatrist and a psychologist, that would show Adams was a "paranoid schizophrenic" who believed he was being followed, thought his phone was tapped and that the smoke alarm in his apartment was actually a camera and tape recorder.

But Assistant U.S. Attorney Steve Gordon told the jurors he would present two psychiatrists who would testify that, while Adams may have had some mental problems, he "never lost touch with reality and had the ability to tell right from wrong." Gordon also said there was "substantial evidence that Adams was "faking" insanity during psychiatric tests.

Adams faces a minimum prison sentence of 20 years to life if the jury decides he was not suffering from a mental disease or defect which made it impossible for him to control his actions or understand that what he was doing was wrong.

If the jury, which is the same one that found him guilty in February, decides he was suffering from such mental problems, then Adams would be committed to St. Elizabeths Hospital, from which he could be released at any time.