Investigators say one person is responsible for last week's killings of a woman and her two children in their southwestern Illinois home.

Authorities said Wednesday they presented their evidence to Monroe County state's attorney Kris Reitz. But Reitz has deferred filing charges until he gets more results from forensic tests.

Maj. Jeff Connor, the deputy commander of the investigating squad, declined to identify the suspect. He assured the community the killings aren't random and says the family was targeted.

Thirty-one-year-old Sheri Coleman was buried Wednesday with her two sons, 11-year-old Garett and 9-year-old Gavin. They were found slain in their Columbia home on May 5.