NEVER, EVER talk to street cops, detectives, or prosecutors without an attorney's advice. These bogus perjury charges happen every day at every level. Spend the money and have a competent lawyer write out your answers. Also, demand in writing, exculpatory facts/evidence at the first legal opportunity.
Another real issue: Prosecutors make their way up through the chain-of-command by how many cases they win. I believe most are good honest people trying to put the bad guys away, but there are always bad apples.
These 3 sum it up perfectly......pardon the language(in advance)