 The survivors of a hit-and-run crash are frustrated. They say detectives could be doing more to arrest a suspect, in this case, from last winter. ABC 15 investigator Melissa Blasius looks at the evidence and gets the opinion of a top legal expert. The hit-and-run crash on February 22 happened near Camelback and 7th Avenue, just after 2 a.m. One woman died. Three other people were seriously injured. You can't hit four human bodies and just drive away and not feel anything after that. Police found the car a 2006 Mazda 6. Inside, evidence seemed promising. The owner's wallet, a cell phone and an open container of alcohol called 4Loco. Good leads to follow, you'd think, but an arrest never came. At first we thought that it was due to a homicide. Maybe they were like concealing certain things for that reason. But then as time has gone on, still no answers. Phoenix police say hit-and-run arrests are hard to make without a confession or an eyewitness who got a good look. The key component is placing the driver of that vehicle behind the wheel. Defense attorney David Cantor knows he's seen hundreds of these cases. That's one of the first things they always look for. If a call is made within a couple of minutes after the accident, you find out who it was made to and then you interview that person. Investigators must also look at where the car and its owner were prior to the crash. You can get video footage, you can retrace with credit card records and you can show this person was here and start drawing out a timeline. Cantor says a complication for this hit-and-run case was a witness report that two people were talking inside the car. Because they can't both be guilty, yet they can both be accused. Unless investigators can figure that out, a driver who's killed someone is still on the road. I'm Investigator Melissa Blazius, ABC 15, Arizona.