GUILTY IA - Richard, 55, & Janet Sweet, 62, shot to death, Manchester, 13 May 2012

The Iowa teenager accused of killing his grandparents is now behind bars.

Police arrested 17-year-old Isaiah Sweet Monday night in Cedar Rapids. He was wanted on two counts of first degree murder in the deaths of his grandparents Richard and Janet Sweet.

Family members found the couple dead on Sunday after coming to their Manchester home for a Mother’s Day gathering.

The medical examiner performed autopsies Monday but the cause of their deaths isn’t being released.

Court documents say Isaiah told a friend he killed his grandparents Friday night by drugging them.

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Either Richard Sweet, 55, or his wife Janet, 62, called police for help with Isaiah Sweet 18 times from March 2011 to April 11 of this year, the records show...

The service calls included Richard or Janet Sweet asking for help with their grandson because he was threatening them, kicking his grandfather, using drugs, arguing with them and not coming home at night.

The most recent call April 11, before the Sweets' death, concerned Isaiah using a lighter and a can of aerosol to make a blow torch... According to the dispatcher, Janet Sweet didn't want Isaiah charged; she just wanted him "back under control."

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A judge says an Iowa teenager who pleaded guilty to killing his grandparents should never get another chance at freedom.

District Judge Michael Shubatt on Tuesday sentenced 18-year-old Isaiah Sweet to life in prison without the possibility of parole in the May 2012 shooting deaths of Janet and Richard Sweet at their home in Manchester...

Shubatt says Sweet is "extremely dangerous" and unlikely to be rehabilitated.

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