What the cover-up covered up

Yesterday's news reports of the death of Matthew Stuart, brother of the locally notorious Charles Stuart, tended to share a minor but interesting inaccuracy.

In 1989, Charles Stuart killed his pregnant wife on the way home from a childbirth class, blamed a (nonexistent) black assailant, and then, when his story fell apart, jumped off a bridge to his death before he could be arrested. But here's how the Globe (and a number of other news sources) described Matthew Stuart's role:

Matthew Stuart spent nearly three years in jail after pleading guilty to helping cover up the killing of Carole DiMaiti Stuart. He said he helped hide the gun believed to have been used by his brother, Charles Stuart, who blamed the crime on a black man.

Or:

Cambridge police have confirmed the death of Matthew Stuart, who helped his brother cover up the fatal shooting of his brother’s pregnant wife in 1989.

But of course Matthew and Charles didn't cover up the killing; it was reported instantly, by Charles Stuart himself, in a 911 call. They conspired and lied, but what they "covered up" was the evidence, not the shooting.

Journalism's rules account for some of the awkwardness in phrasing. We can’t call it "murder" or call Charles Stuart the killer, since he wasn’t charged and didn’t confess. So what’s the most economical edit that makes the report accurate? Is there a neater solution than "pleaded guilty to helping conceal evidence about the killing"?