My question involves criminal law for the state of: Pennsylvania
About a year and a half ago I was the victim of an armed robbery in my apartment, in which $2,500 cash was stolen. At the time, I was involved in some "not-so-legal" business, and I was sure one of two assailants was an associate of mine. While being interviewed by police, they'd pretty much put 2 and 2 together and assumed what was going on. That being said I couldn't really report the property loss for legal restitution.
Present day; The defendant made bail and contacted me to talk. We met and he claims that my & the police's suspicion is completely situational and he's innocent. He says he has receipts from purchases made during the time of the robbery etc...
He also said that he'd be willing to pay me the $2,500 I'd lost just as a sign of good faith to show that he was not the one. The main point to this conversation was he's facing 10-15 years for Armed Robbery and Conspiracy to commit armed robbery, and I'm the only credible witness.
Question 1
Can I, as the victim/witness, legally accept this money outside the confines of the justice system? I.E. promissory note, or gift? If I take this money, could it be interpreted as tampering with a witness via bribe? If I did decide to switch my stance and testify in favor of the defense, could it be interpreted as perjury or can changing your opinion based on evidence be a hearse exception?
Question 2
Do I as the victim and witness, have the right to see the evidence put forth by the defense &/or prosecution? He claims that the DA and police force are breaking a bunch of different laws and using irreverent evidence against him. I'd really like to see the evidence gathered by the defense for myself to determine if he truly could have done it.

