Ronald O'Rourke, 46, of Crystal Lake is charged with murder, home invasion and burglary.
"There are allegations. We made these on the record today in open court that she had concerns about him, he had been to her home in the past and she had expressed her concerns about him entering her home while she was away and obviously the worst possible scenario was realized after returning home Saturday after doing errands," said Joe Birkett, DuPage County state's attorney.
The arrest comes after four unrelated murders in Hanover Park in two weeks.
Police Monday said they also arrested and charged a 16-year-old boy as an adult in the stabbing death of 23-year-old Diontae Roberts Cherry, a Hanover Park man. That teen remains jailed on bond.
The mayor wants residents to know the suburb is safe.
"All my customers are just flabbergasted. They don't know what to say. I mean it's scary," said Claudette Zito, Prairie Station Pub.
So far, there have been four slayings in the northwest suburb in the last two weeks; three in the last four days, including Howat.
"It was a blow to all of us. Really sad," said Kevin Kowalski, Howat's friend.
On Thursday, a pregnant mother of two allegedly died at the hands of her live-in boyfriend, who has been arrested and charged in the crime.
These incidents have left some Hanover Park residents on edge. But Hanover Park Mayor Rod Craig says it's safe.
"We don't have a wild man running around with a machete kind of a thing. This is domestic violence, that's well documented. There's a history of that problem with individuals. It just happens to be hitting our community hard right now," Craig said.
The mayor was out most of the weekend talking to residents, trying to make them feel safe.
Investigators say they are also working on another ongoing investigation. On May 23, Jesus Sanchez was shot to death in front of his house.
Village officials say they're sponsoring an anti-violence forum that was in the works long before the rash of murders.
Hanover Park residents and community leaders were at a loss Sunday over the sudden increase in violence.
"Diontae [and] his younger brothers, you can't get any closer," said Harold Cherry.
"I get up, and I open the garage, I see all of this tape all over the place. I say ot the police, 'What, you got a crime scene over there?'" said neighborhood resident Maria Dinuzzo.
Diontae Roberts Cherry's brother, Michael Cherry, was also injured.
"He goes to the car, and the next thing you know, I'm being attacked again. I hear him say, 'I got stabbed,'" he said.
"I've been living in Hanover Park for 30 years. I figure no problems. I don't carry a lock or anything on my bike. I figure the crime rate wasn't that bad here," said Rich Wisniewski.