SANTA ANA (CBS) — An attorney’s questionnaire has given the public a glimpse into the mind of a imprisoned Seal Beach salon owner accused of the largest-ever mass murder in Orange County.

Scott Dekraai, 43, pleaded not guilty in November to eight counts of murder and one count of attempted murder after eight people were killed and one person seriously injured when Dekraai allegedly went on a shooting rampage at the Salon Meritage on Oct. 12 of last year.

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But after a civil attorney representing relatives of his ex-wife Michelle Fornier and their son in a wrongful death lawsuit contacted him with a list of written questions, Dekraai was surprisingly cooperative in his response.

KNX 1070’s Mike Landa reports attorney Eric Traut said Dekraai was forthcoming on several of the questions but refused to answer perhaps the most important one: “Why did you kill your ex-wife and others?”

“In that instance he said, ‘I take the Fifth [Amendment]’, that’s what he wrote,” said Traut.

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Traut said Dekraai also pleaded the Fifth when asked what events led up to the massacre.

Dekraai did reveal some previously undisclosed financial information, including his $1,760 monthly disability payment for a workplace accident.

“It’s surprising to me that he would even respond,” said Traut. “I’ve had other cases against criminal defendant who just ignore me.”

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Another court document also revealed Dekraai may not have fully disclosed his net worth: a legal brief purports to show he owns two properties and has approximately $250,000 in cash and stock holdings.