This article has a few more details relating to the timeline.
Shooting in Columbus' Weinland Park neighborhood kills dentist, wife
Spencer didn't show up at the dental office on Tuesday (Dec 30) morning. A colleague called police at 9:03.
At 9:22 a.m., an officer reported there was no answer at the door. He left.
At 9:57 a.m., a man called police, saying he was at the home and could hear children inside.
Shortly after 10 am a man called police saying he could see Spencer lying on the floor beside a bed.
Police got a warrant and entered the house and found the children.
The friend who saw Spencer's body through a window told police he had last spoken to Spencer the day before.