The jury convicted Lucas of first-degree murder in the May 4, 1979, killings of Suzanne Jacobs, 31, her son, Colin, 3, and the Nov. 20, 1984, death of University of San Diego student Anne Catherine Swanke, 22.
Jacobs and her son were found in their Normal Heights home with their throats slashed.
Swanke's throat also was slashed. Her body was found on a remote hillside in Spring Valley.
Jurors also convicted Lucas of the attempted murder of Jody Santiago-Robertson, 34, of Seattle. She survived a June, 1984, attack in which she was choked and her throat was slashed.
Lucas also was convicted of kidnaping Robertson, who testified for the prosecution at the trial, and of kidnaping Swanke.
Lucas was acquitted in the death of Gayle Roberta Garcia, 29, a Point Loma realtor who was found with her throat slashed in a vacant Spring Valley house on Dec. 8, 1981.
Jurors were unable to convict Lucas in the deaths of Rhonda Strang, 24, and Amber Fisher, 3, both of Lakeside. Strang was baby-sitting the child when their throats were slashed Oct. 23, 1984. The jury foreman told Hammes that, after taking four or five votes, the jury was deadlocked, 11-1, for conviction.
Lucas was arrested in December, 1984.