A man standing trial after being accused of robbing a bank in California was likely left with a bad taste in his mouth after an apparent bid to convince the jury he was insane proved unsuccessful . While he was testifying at San Luis Obispo Superior Court last week , Andrew Gilbertson pulled some feces out of his pants and ate it . He was on trial for robbing a Bank of America branch in the central California city in 2013 . Scroll down for video . Andrew Gilbertson was standing trial in San Luis Obispo Superior Court in California for a 2013 bank robbery . While he was testifying , the 40-year-old defendant reached into his pants , pulled out feces and then ate it . Gilbertson 's attempt to convince the jury he was insane did n't work and he was found guilty of robbery . Gilbertson , 40 , was pleading not guilty by reason of insanity and claimed he heard voices in his head , according to the San Luis Obispo Tribune . His defense attorney , Brian Buckley , apologized after the excrement eating . Buckley said : 'When I said this was going to be an unusual case , that was n't what I was expecting . ' Despite his unorthodox attempt to convince the jury he was insane during the robbery , Gilbertson was found guilty of robbery and burglary . Deputy District Attorney Dave Pomeroy told the jury , who took about half a day to hand down the verdict , that Gilbertson was sane when he robbed the bank and when he ate his poop . Pomeroy said : 'That was upsetting a couple of days ago . 'Obviously , it was designed to produce emotion . ' He added that Gilbertson showed off his hands during the stunt to 'be sure you all clearly understood what he had in his hand and what he was doing ' . The district attorney argued Gilbertson pulled off the heist because he 'really , really likes methamphetamine ' Gilbertson said the Virgin Mary told him to disguise himself and rob the Bank of America in San Luis Obispo . He has previous convictions for sexual battery , aggravated battery and failure to register as a sex offender . Before he ate his waste , Gilbertson told the jury the Virgin Mary told him to wear a disguise and rob the Bank of America , KSBY reported . The district attorney argued Gilbertson had a much different reason for pulling off the heist . Pomeroy said : 'He just wanted methamphetamine . 'He testified that he really , really likes methamphetamine . ' Gilbertson has previous convictions for sexual battery , aggravated battery , failure to register as a sex offender and car theft . A sentencing date for his latest conviction has not been set .
Andrew Gilbertson on trial at Bank of America in California . He was accused of wearing disguise and robbing San Luis Obispo Superior Court in 2013 . 40-year-old defendant was pleading not guilty by reason of insanity . Prosecutors argued he was sane during robbery and when he ate the poop . DA said he pulled heist because he 'really , really likes methamphetamine ' Jury deliberated for half day and found him guilty of robbery and burglary .