This is a difficult case as it is laid out. There were many comments and emails from readers with good questions and suggestions on what type of evidence should be collected.
Let me put what the prosecutor looks at. If these are the only facts, we cannot prove the case beyond a reasonable doubt. The police have probable cause to arrest based on the witness statements, but it is not even clear the case would survive grand jury. With just these facts, the question arises of whether we should prosecute the case. Is this the case where innocent men might be convicted? If we choose not to go forward, how do we tell the victim?
Prosecutors receive cases like this every day. It's called an incomplete investigation. We are not investigators, but many time the prosecutors have to pick up where the police left off. Once police officers put the cuffs on, they move on to the next case.
One suggestion was to get the Facebook messages between the victim and boy she was talking too. That is the first thing I would do. Then, I would find out where the boy posted his messages from. A cell phone? We would obtain a search warrant for the cell phone to get the messages. Does the boy's Facebook page contain a video? Then, we can access his videos on his phone through the warrant too. Maybe these boys took a video of the incident which would show what happened.
If the victim reported the crime early on, we would obtain a search warrant for the house where it occurred to try and find evidence too.
Every investigation starts with obtaining some evidence and then any good prosecutor follows all the leads from that piece of evidence. One of my mantras is that every file has the potential to turn into numerous files. A gun case means we might be able to find out who sold the gun to the person. One robber probably did more in the area. If we get a cell phone of a rape, there is a good chance more exist on there.
It creates a never ending cycle.
Once we exhaust the possible evidence, we can make the decision. Again, if no other evidence existed but the victim's word this case would be difficult, if not impossible to prove. Those are the worst conversations with victims. They were robbed or raped and are certain we have the right person, but there is nothing to corroborate the identification. With what we know today about DNA and wrongful convictions, can I as a prosecutor justify the prosecution of that person? Does the victim deserve their day in court?
This is the cases we must decide every day. Prosecutorial discretion is a great power that we need to wield responsibly and still respect the rights of the victims. There are rarely easy choices in this line of work.