In a discovery that police called "gut-wrenching," a woman was found dead in a St. Paul house late Friday while two children were found unharmed in another room.

The discoveries happened about 9:30 p.m. in the city's Frogtown neighborhood.

Police were called to a house in the 500 block of Charles Avenue after the woman had failed to pick up a child at a day care. A family contact picked up the child and drove to the family's home, but no one answered the door, according to St. Paul police.

When officers went inside, they found blood and then the woman, police said, adding that she was gravely injured and soon died at the home. Her death was St. Paul's 13th homicide of the year.

On Saturday, police announced that a 27-year-old Minneapolis man had been arrested and was being held on suspicion of murder. The Star Tribune does not generally name suspects until they're charged.

Police spokesman Steve Linders said the man was arrested without incident about 10 a.m. Saturday in the 300 block of Arundel Street in St. Paul.

Police are working to establish the relationships among the suspect, the victim and the three children, he said.

The children — one who was at day care Friday and two who were at the home — are with someone who is "close" to the family, Linders said.

"Anytime anyone is murdered in our community, it's a concern, and the concern is even greater when there are children and young people who are present and experiencing great trauma from this violence," Linders said.

The children are all under 13, he said.

Police have not released the woman's identity or how she was killed pending autopsy results. A hearse was parked outside the home around 10 a.m. Saturday, and a portion of the block remained taped off.

The suspect has a criminal record that includes convictions for financial fraud, theft, fourth-degree assault on a police officer, first-degree aggravated robbery, domestic assault and disorderly conduct.

John Tolo, who lives a few houses down from the house, said a man, woman and three children had lived in the house for about two years.

Tolo, executive director of the nonprofit SafeCity Project, which provides community outreach and seeks to connect neighbors, said the family often spent time in their yard with a next-door neighbor but did not appear to engage in larger neighborhood events.

"We try to connect with parents and kids in the neighborhood," he said of his group, "and we were never really able to connect with them."