Police say Timothy Fradeneck admitted to strangling his wife Christie Fradeneck, 37, and children Celeste, 2, and Timothy, 8, using a USB cord, late Sunday night.
Fraderick, 37, was arraigned on seven counts including first degree murder, felony murder and child abuse.
Due to the severity of those charges, Timothy Fradeneck is being held without bond. He is facing life in prison without parole and is due back in court April 28.
"This might be the worst we've seen in a long time." said Macomb County Prosecutor Eric Smith. "All three were asleep when each one happened."
After family hadn't heard from Christie all day, police say Monday night they arrived to the Fradenick home on Cushing street.
"(Police) wanted to see his wife and children, he said they were sleeping," Smith said. "And instead of leaving, they demanded to see those children."
Fradeneck, appearing lucid, confessed to the three murders within minutes, police say.
"He had been contemplating it since last August," Smith said. "And the opportunity arose that evening."
Fradeneck has not said why.
"I would like to enter a plea of not guilty by reason of mental insanity," Fradeneck said in court.
Smith says Fradeneck had not been taking his medication, but he is unsure if it was for any mental issues.
"I tried to kill myself sir," Fradeneck said in court to the judge.
"This was not an 'I'm hearing voices' 'I need to protect them' type of thing," Smith said. "For some reason, he had been contemplating this and went down the line and murdered all three of them."
Both families, too distraught to speak, are left consoling each other. And left planning three funerals.