That's my question too. More criminalization of gunowners?
"the ATF seized 10 weapons and parts for machine guns, all of which the collector had illegally imported from Canada."
To me, this indicates that this man is not a law abiding citizen. I am now wondering why he wasn't charged with these crimes and serving time when the Makarov murder took place.
18 USC §3144. Release or detention of a material witness.
If it appears from an affidavit filed by a party that the testimony of a person is material in a criminal proceeding, and if it is shown that it may become impracticable to secure the presence of the person by subpoena, a judicial officer may order the arrest of the person and treat the person in accordance with the provisions of section 3142 of this title. No material witness may be detained because of inability to comply with any condition of release if the testimony of such witness can adequately be secured by deposition, and if further detention is not necessary to prevent a failure of justice. Release of a material witness may be delayed for a reasonable period of time until the deposition of the witness can be taken pursuant to the Federal Rules of Criminal Procedure.
The "Material Witness Clause" can be abused to hold a person of interest for however long the police want, with no charges nor apologies. Meanwhile they can be interrogated round the clock or whatever seems to amuse the prosecutor and their property can be tossed and re-tossed in search of evidence. And it's all legal.