Chesapeake, Va. -- Attorneys tried to bolster their insanity defense for sniper suspect Lee Boyd Malvo with testimony from a cult expert who said Malvo's childhood could have made him vulnerable to brainwashing by sniper mastermind John Allen Muhammad.
According to earlier testimony, the 18-year-old's mother, Una James, moved from town to town and school to school as she looked for work in the Caribbean, leaving her son with a string of people willing to take him in.
That pattern, the defense claims, made Malvo vulnerable to brainwashing by Muhammad.
"Instability is a factor in indoctrination,'' Paul Martin, a psychologist and former cult member, testified Friday. "People seek relief from that instability, that sense of insecurity in their life.''
Martin has not interviewed Malvo or Muhammad, but offered general testimony on how brainwashing typically occurs, and answered hypothetical questions about how the circumstances of Malvo's life apply in the context of indoctrination.
He did not give an opinion on whether Malvo was brainwashed.
Prosecutors strongly objected to Martin's testimony, saying he was not qualified to offer opinions on the relationship between Malvo and Muhammad.
Fairfax County Commonwealth's Attorney Robert F. Horan Jr. argued that any testimony about indoctrination is irrelevant, because brainwashing is not a diagnosable mental illness that can lead to insanity.
"This specific testimony is designed to get the jury to think about things that have nothing to do with this case,'' Horan said.
Circuit Judge Jane Marum Roush allowed the testimony but limited its scope.
The capital murder trial will resume Monday with testimony from Dewey Cornell, a clinical psychologist at the University of Virginia who was appointed by the court as the defense's mental health expert.
Last month, a jury convicted Muhammad of capital murder and recommended death for one of the 10 sniper slayings that terrorized the Washington, D.C., area over a three-week period in October 2002.