Do the Regulars have anything to add?

Hint 1 of 7:

One thing you need to know is that unlike many of the other cases in this
series, the Irregulars have a lot to add that Watson and Holmes can't learn
on their own.  People that you must visit with the Irregulars are noted.

Hint 2 of 7:

You might want to get a copy of the police report.  Send the Irregulars to
visit Lestrade.

Hint 3 of 7:

You can get Jasper Meek's report with the Irregulars.

Hint 4 of 7:

H. R. Murray has an analysis of the evidence.  The Irregulars can get it.

Hint 5 of 7:

Edward Hall has a little bit that he can tell you about Attard.

Hint 6 of 7:

Disraeli O'Brien mentions Twiggs and Maude's past history.

Hint 7 of 7:

Langdale Pike knows something about Jaquard's love life.