In May 2020, Steven and Elke’s infant son, Lucas, died of a brain injury consistent with shaken baby syndrome. Steven says he is currently the subject of a homicide investigation into his son’s death but insists that neither he nor Elke would have ever hurt their baby.

The couple says they recently learned they are expecting their second child.

“I definitely do have mixed emotions about it,” says Steven. “I can’t say I’m not excited, but I don’t know what it means with the investigation on Lucas’s case.”

Elke says that if Steven goes to prison, she’s worried about being a single mom.

Steven's mother, Melissa, claims Elke, not Steven, is responsible for Lucas' death. “I think it’s the most irresponsible thing on the planet. I can’t even fathom what is going through her head,” she says.

Watch the conclusion of this two-part Dr. Phil, “’Who Killed Baby Lucas?’,” airing Friday to find out what Melissa says she plans to do once her new grandchild is born.

Check your local listing to find out where you can watch.

WATCH: ‘I Don’t Really Have Any Strong Alibi,’ Admits Father Who Denies Causing His Infant Son’s Fatal Injuries

TELL DR. PHIL YOUR STORY: Have you been accused and want to clear your name?