Costa Mesa police say they'll never know if a man meant to kill himself when a homemade bomb detonated in his house.
The Los Angeles Times reports that after searching his home, authorities can't determine whether 52-year-old Kevin Harris was committing suicide or died by accident.
A rambling 17,000-word essay was found online, believed to be penned by Harris, expressing a deep fear of government.
Neighbors described Harris as an odd but harmless eccentric whose house was wrapped in aluminum foil.
His mother told the Times he had been diagnosed with a mental illness, possibly schizophrenia.
On Sunday, Harris was seen lying in his front yard, but refused medical attention when paramedics responded.
An explosion rattled the neighborhood a short time later, and he was found dead.