"There's nobody knows we're (expletive) here," Webber says. "We're doing this on our own."The transcript indicates that Webber produces a form that, once signed, will state that Siler gave his consent for the officers to search his home. Siler apparently refuses to sign it. The beating resumes.
This illustrates an obvious problem with this kind of consent form: it's fairly easy to pressure suspects into signing--recall how common it was in the Soviet Union for people to be forced to sign "confessions." The fact that it's easy to coerce cooperation makes it easy for suspects to claim that their cooperation was coerced after the fact. Of course, there's a simple technical fix: have the police take audio and visual recordings of every interaction they have with suspects. These recordings could be timestamped and signed in order to prevent tampering after the fact, thus demonstrating that the police hadn't coerced cooperation.
Alaska and Minnesota already record all police interrogations but the practice isn't universal in this country. As usual, there's resistance from law enforcement, with the usual argument being that it would hinder interrogation. But of course, that's only true if the police are using proscribed tactics, which isn't exactly something that should be reinforced.