I saw that video of the three member band. IMO it looks like nothing more than a private get together between friends. I'd hardly call it a concert (like some are calling it) that would attract many people from the area.
And, since it did take place in Dec., wasn't the owners daughter living there then (in the particular house these band members were filmed)? I'm sure they've already questioned her by now about people who may have been to the home over the last several months. JMO.
They look like students to me but this may not be accurate cos it's filmed with very little light..I'm sure LE can brighten it up tho..I've seen it asked but not answered if the daughter has any kids..Odd if she doesn't unless she's just a nice person & allows the former UV students to attend these "concert/s" there like they had in the past? Maybe even the perp!
It seems to me it's called a "concert" cos the band is promoting itself on youtube.