(CNN) -- All five members of a family found slain inside a Beason, Illinois, home early this week were beaten to death, police said Thursday.
Police officers stand patrol outside the Gee household late Monday evening.
A pathologist determined that the five -- Raymond Gee, 46; Ruth Gee, 39; and three children -- had been beaten, Logan County Sheriff Steve Nichols told reporters. "All the injuries at the scene were from blunt-force trauma."
The three children were identified as Justina Constant, 16, Dillen Constant, 14, and Austin Gee, 11.
A 3-year-old girl remained in critical but stable condition Thursday at a hospital, Nichols said.
He said he would not divulge or speculate what the family was beaten with, and remained tight-lipped about many aspects of the deaths, including when authorities believe they occurred.
Beason is in central Illinois, about 45 miles northeast of Springfield, the state capital.
A task force has been formed with officers from several different agencies to investigate the homicides, the sheriff said. Processing of the crime scene concluded Wednesday afternoon, and "hundreds of seized items" are being processed, he said. "Forensic evidence in this case is significant."
The sheriff has said authorities received a 911 call about a possible shooting at the home shortly before 4:30 p.m. Monday.
Nichols said authorities are looking for a gray-primer-painted pickup truck that was seen in the area Sunday night. "We'll take any tip that anybody has," he said.
A tip line has been set up at 217-732-3000, Nichols said.
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