I Still Believe will be produced by Jon and Andrew Erwin, who will also direct from a script by Jon Erwin and Jon Gunn.
Twain has signed on to portray Terry Camp, mother to Jeremy, while Robertson is set to star as Melissa Henning, who starts as Jeremy’s love interest and eventually his wife.
Apa and Sinise will play true-life father and son Jeremy and Tom Camp.
Sinise has kept himself busy with television projects such as CSI: NY, from 2004-2013, and the recent Criminal Minds: Beyond Borders.