[OldMissileer]

Aren’t there small accessories that resemble a mesh bag that attaches to a semi-auto pistol’s slide to catch the brass as it ejects?

Yes. Back in the early 1980's I bought one for my Colt 1911s. You replace the right side grip with a plastic one that has a connector for the catcher.

It worked quite well but played hell with my sight line until I got used to seeing it in my field of view.

[Bloody Sam Roberts]

It worked quite well but played hell with my sight line until I got used to seeing it in my field of view.

But for someone using the piece to commit murder or armed robbery, if not too bulky or 'kludgey', the catcher would serve better than hunting around for brass.