Charges were brought against EG. She had a jury trial for child endangerment for taking her infant daughter MH to Olive Garden while allegedly high on marijuana. The jury acquitted her, largely because there was no evidence that she was actually intoxicated when she drove. Lucas was still missing at the time.
Then, the PI came, earned her trust/manipulated her and they found Lucas on the second day he spent with her. That was a combination of him taking her to places that LE had narrowed down, telling her it will be alright, and reading her body language as they drove. EG was arrested that night for obstruction of justice and providing false information to law enforcement.
After 72 business hours, she was released. The DA was not ready to proceed with those charges, likely because that would start the process of turning information over to EG's attorney. The DA likely wanted to wait for the rest of the investigation and autopsy to play out before showing any cards. So, she was released while LE and the DA built a case.
They are not to blame for the suicide. Only one person is. LE and the DA were making the best decisions to try to get a potential murder charge to stick.
As to how Lucas's case proceeds, it would have to be with charges against someone living. If EG is the only wrongdoer, there will be no trial.
But, the DA has said he is committed to pursuing the investigation until he is able to provide the family and the community with all the answers he can.