This is from an AP article, but I suggest it’s typical of the press generally. The AP is reporting on a case involving the drunk driver-involved deaths of two children and the immediately subsequent shooting death of the drunk driver. The father of the two children is accused of

killing a drunk driver in a fit of rage after his two sons were fatally struck in 2012 on a rural road in Southeast Texas.

His defense attorney says [the father] is a good man, a grieving father, and not a murderer. At the same time, his defense hasn’t publicly suggested who else might be responsible for [the drunk driver]’s shooting death.

Notice that last. According to the press, the father must, if not outright prove his innocence, at least offer plausible alternatives.

No. The press’…misunderstanding…notwithstanding, no such defense obligation exists. It’s on the prosecution—the government—to prove any defendant’s guilt; no police work, no investigative work at all, is required of the defense. Full stop.