Theranos founder Elizabeth Holmes is trying to turn a visit to her home this summer by a key prosecution witness into a “ticket to a new trial,” prosecutors claim. Convicted by a jury in January for defrauding investors in her now-defunct Palo Alto blood-testing startup, Holmes is scheduled to be sentenced Oct. 17 on four felony counts. Legal experts anticipate Holmes, 38, will receive a multi-year prison sentence. But recent court filings and a judge’s order have thrown that sentencing date into doubt. Earlier this month, Holmes filed a flurry of motions in U.S. District Court in San Jose to …