1. He had sole care and custody at the time the baby was reported missing (mom and dad did not reside together at that time)
2. He told police he was one place when in fact video surveillance puts him at another.
Authorities say they have surveillance video of Graham taking the child to a convenience store the night of her disappearance, according to KHSL. The station reports that Graham told them he took the baby to the store and then drove the short distance back to their home, but officials say the video shows him
driving in the opposite direction of the home when he left the store, and heading back towards the home about an hour later.
Officials say Graham didn't show remorse for his daughter's disappearance, didn't ask about the efforts to find her, and refused to take a lie detector test, reports the station.
http://www.cbsnews.com/news/report-missing-babys-father-killed-in-shootout-with-police/
3. Police located a pacifier that had Ember's DNA on it in near Ono, which would be on a route that the video showed Matthew heading the night of her disappearance despite him telling police he headed back home (opposite direction from Ono).
4. As soon as the DN was identified as a match to Ember he went on the run from police, taking his mother's weapon and cash from their home as he went.
5. He opted to die in a shootout with police (suicide by cop) rather than face the music.
Seems pretty compelling to me. RE prosecutor taking the case - what case? Mr. Graham ran as soon as he became a suspect. A case never had a chance to be presented to a prosecutor. The suspect is dead. A dead man cannot be tried.