Juries are interesting.
There have been many no body cases where convictions came swiftly. Once the jury is convinced that there's foul play and that the person is no more, juries take very seriously whatever evidence the perp did leave behind.
Such as blood in the house, or on a gate. Videos. Shuffling of cars. Turning off of phones or other devices. Leaving a device somewhere during the time the crime was likely committed. Fingerprints on shovels. DNA on shovels or other tools. GPS and Google data.
They also listen carefully to witness testimony. Statements about the defendant's relevant past character and behavior, especially in regard to the victim. Witnesses that may have observed violent behavior or abuse. Witnesses who were asked to say something in favor of the defendant that constituted a lie. Statements about possible motives and triggers.
Witnesses can also establish discrepancies and lies concerning other evidence. A lying defendant always makes a jury take notice (even if the defendant isn't on the stand, if they've made SM or public statements that are at variance with each other, that's very much the kind of thing juries want to see).
In this case, the expert witness testimony about SM might be crucial and quite damning. Maybe.
