ST. PAUL — Authorities said a woman whose ex-boyfriend held her hostage and assaulted her convinced him she needed to go to the library in St. Paul where she secretly called police.

Officers arrested 22-year-old David Wilkes who told police he had randomly run into his ex-girlfriend at the library. Two restraining orders bar Wilkes from having contact with the woman.

A criminal complaint said the woman told investigators she broke up with Wilkes about a year ago after he assaulted her, but that she let him stay at her apartment because she was too afraid to refuse him.

Authorities said Wilkes was armed with a knife and held the woman captive for three days.

On Aug. 4, she convinced him that she needed to go to the library to fax her employer her time sheet.