LYONS, Ill. (AP) — A man suspected of concealing the deaths of his mother and sister nearly a year after their bodies were found buried in the backyard of their suburban Chicago house has been arrested on felony charges, officials announced on Thursday.

Lyons Police Chief Thomas Herion said Michael Lelko, 45, will be formally charged with two felony counts of concealment of a death. He said a federal investigation also is ongoing that could lead to federal charges connected to his alleged cashing of his mother’s monthly $1,000 Social Security checks for years after she died.

Herion said Lelko was not charged in the deaths of 79-year-old Jean Lelko and 44-year-old Jennifer Lelko, since the medical examiner’s office could not determine how either one died.

Herion said Michael Lelko’s 41-year-old brother remains the subject of an investigation but as of Thursday afternoon he had not been charged. Both were in custody on Thursday and Herion said if John Lelko was not charged within 48 hours he would be released from custody. Herion said John Lelko could face obstruction charges because he initially told police that his mother and sister were alive and living elsewhere, even though he knew they were both dead.

Thursday’s announcement comes about eight months after police discovered the bodies in the back yard during a well-being check at the residence. Both bodies had been buried in plastic tubs that had been sealed with duct tape.

Herion said Michael Lelko told police that his mother had died in 2015 after his sister pushed her down the stairs and that he buried his sister in the yard in 2019 after she became ill and died. He said Lelko said the sister had died of COVID-19, though Herion said he didn’t believe COVID-19 existed in 2019, and Illinois officials have said they believe the first COVID-19 death in Illinois was in March 2020.

“When I interviewed Michael, he admitted that he buried his mother and his sister in the yard,” Herion said. “John did not give any statements pertaining to whether he participated in that.”

Herion said charges were not filed for several months because the bodies were not positively identified until this year. Both men, were taken into custody when the bodies were found but were released without being charged.

The charges mark the final chapter in the bizarre story that began with a check of the house, located in the community of Lyons, about 14 miles (22.53 kilometers) southwest of Chicago, after it was determined there was no running water. Herion said there were no operable toilets at the home, and several bags of urine and feces were found inside.

Herion said items such as Star Wars toys were stacked up to the ceiling at the time the bodies were found, and the home was so cluttered that the brothers climbed in and out through windows.

It could not be immediately determined if Michael Lelko had retained an attorney. Messages were left with the Cook County State’s Attorney’s office and the Lyons Police Department.

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