BOSTON — Massachusetts’ highest court has upheld the 2008 murder conviction of a former radio reporter found guilty of killing his wife by poisoning her with antifreeze.

The state Supreme Judicial Court said in its decision issued Monday the evidence of James Keown’s guilt was “overwhelming.” Keown is serving a life sentence in the 2004 death of Julie Keown.

The court rejected arguments that the judge presiding over the trial was wrong to allow evidence from Keown’s laptop and his internet search results, which included “antifreeze human death” and “poison recipe.”

Authorities said the former Missouri man killed his 31-year-old wife by spiking his wife’s Gatorade with antifreeze while the couple lived in Waltham.

Keown’s lawyer had argued his wife could have accidently ingested the chemical or taken her own life.