Earlier, published reports indicated that the ex-boyfriend, a 28-year-old Countryside man, had told police that he was gambling at the riverboat at the time of the shootings. Video surveillance from the casino seemed to corroborate that story.
But Jacob Nodarse, who was arrested about 36 hours after the shootings at his parents' home in Florida, is also seen in the video, the newspaper reports.
Both men are being questioned in the deaths of Jeffrey, Lori and Michael Kramer, though no murder charges have been filed.
Nodarse, 23, appeared at a Fort Myers, Fla., court Thursday wearing a restraining jacket used for prisoners who may attempt to injure themselves.
Prosecutors asked for a $1 million bond, but the judge issued no bond. The judge also ordered a psychological evaluation.
Nodarse is under twenty-four hour supervision in the mental health ward of a Florida facility. His "direct observation gown", which has no buttons or straps, is made of tear-resistant material connected by velcro and designed to prevent inmates from injuring themselves.
Sources tell NBC Nodarse has given police a "full confession."
Meanwhile, 1,100 miles north detectives were searching a dumpster behind a Terre Haute, Indiana IHOP where "a substantial amount of evidence was found relating to the triple murder," sources say.
A manager at the IHOP told WBBM Radio that he saw detectives remove a plastic bag containing a sneaker, and heard they recovered a gun. Indiana State police, however, will not confirm this information.
Nodarse's parents cooperated with the fugitive task force that descended on their house to arrest the son, according to sources.
Nodarse's mother works for the prosecutor's office in Lee County, Florida, where Nodarse fled after the murder Tuesday morning. As of today she's on a leave of absence.
Detectives arrested Nodarse about 36 hours after police received a 911 call from a woman hiding in a closet in the Kramer's home while the family was being shot to death.
To find Nodarse, detectives tracked his cell phone signal from Illinois. He was found sleeping barefoot in a gray van outside his family’s house in Lehigh Acres in full view of cameras.
The ex-boyfriend has been in custody in a Darien jail since Tuesday. Officers have until Friday morning to charge him, otherwise he must be released under Illinois law.
As of now, police contend that the Kramers were targeted in the attack.