A Grove City man fatally stabbed the mother of his three children yesterday when she arrived at his apartment to pick up two of them after a weekend visit, police said.

At his father's request, according to the 911 recording, a 13-year-old boy called police just before 9 a.m. and told the dispatcher: "My dad just killed my mom. ... She's laying in the grass in front of our apartment."

His 4-year-old sister could be heard squealing in the background.

Candice R. Roberts, 36, had arrived at Jeremy A. Roberts' apartment at 3246 Townhouse Dr. in Grove City for a quick pickup — she left her car's engine running.

She and her ex-husband had a brief argument before she was stabbed outside the apartment, police Capt. Jeff Pearson said. Neighbors said the weapon appeared to be a large kitchen knife. Roberts covered his ex-wife's body with a blue sheet and left her in the yard.

The boy, after calling 911, handed the phone to his father. "We can discuss all the details when you get here," Roberts calmly told the dispatcher.

During the five-minute call, Roberts, 38, can be heard talking to his son and daughter. According to birth records, the couple, who divorced in 2010 after 14 years of marriage, also have a 16-year-old daughter who was not at the home yesterday.

"Your sister is a good big sister ... she'll take care of you guys," Roberts told his children. Roberts was taken into custody and will be charged with murder, police said.

A man who answered a phone at a number listed for Candice Roberts identified himself as her stepfather and said the family had been advised by police not to comment.

At the end of the 911 call, when the dispatcher told Roberts to go to the front door and wait for police, he asked if he could kiss his kids goodbye.

"I love you guys," he said. "Wait. One more hug. I love you guys."