[Tax-chick]

The vandal — a 30-year-old homeless sources said has an extensive criminal history — was undeterred.

A 30-year-old homeless *what*? I thought this might be a new workaround to avoid mentioning a person's sex, but the next sentence starts, "He ...," so it isn't that.

[Harmless Teddy Bear]

I would say that vandal is probably the subject with homeless being the adjective.

The sentence would make much more sense like this.

The 30 year old homeless vandal, with an extensive criminal history according to sources, was undeterred.

But news writers seem to think that dashes are cool and commas outdated.