Published: Jul 03, 2013 7:14 PM EDT
Updated: Jul 06, 2013 10:27 AM EDT

FORT MYERS, Fla.- Fort Myers Police Chief Doug Baker is answering questions about the state attorney's office's decision not to prosecute Henry Brunson for the murder of 16-year-old Kanasha Isaac. Isaac was shot and killed while sitting in a car outside Fort Myers Ale House on Colonial Boulevard in February.

On Tuesday, the state attorney's office announced it did not have enough evidence to continue moving forward with prosecuting 24-year-old Brunson. Documents show four main reasons why they aren't moving forward, and three of those reasons deal with witness testimony. The main key witness in the case changed her story and was no longer considered reliable.

Baker says he's frustrated and disappointed to lose the case at this point. "It's extrememly frustrating. We have a lot of man hours, investigation hours, collection, submission, it's important to make the case quick but you want to hold that person accountable. To lose any case is disappointing."

"The whole balance in this case, that surrounds this case is one witness who identified Brunson as the shooter, knew him 20 years, and then changed her story after the arrest. The smoking gun in this case was a witness and it was a witness who over time, turned out not to be credible."

Baker says his officers did nothing wrong in working the case. "I'm very confident in our detectives' ability, our supervisors, our patrol and operations. The issue is the cases are not perfect. I cannot control or require anyone to be truthful, can't do it."

Besides the unreliable witness testimony, the state attorney's office questioned why a detective threw away a gun residue swab used on Brunson, instead of taking it into evidence. Baker says that's because the gun residue test never happened. "This was closely 8-10 hours after the scene so we would not collect a gun shot residue swab from anyone. What this was, was to elicit a response, the gun residue swab kit was not utilized, several other swabs were utilized. What the detectives were trying to do was to gain a physical response from the suspect when he realized what the detectives were doing. So it was an interview technique to gain a response from the suspect. There was a prop swab used but the detective didn't get the physical response he was hoping for, so he discarded it. Now would I have hoped he would have held onto it? Yea I would. We'll look at it and compare against policy."

Baker says he still believes they arrested the right man, and detectives will continue to work the case. If FMPD discovers new evidence, officers have until about mid-August to arrest Brunson again for the crime, before his right to a speedy trial runs out, according to prosecutors.

Brunson's attorney, Robert Harris, says he believes police arrested the wrong person from the beginning. "The more I looked into it, the more I realized the police made a grievous error  to arrest Bruson in the first place. They arrested him 8 hours after the homicide which doesn't seem like enough time to fully investigate."

Harris believes the key eyewitness had alterior motives when she identified Brunson as the shooter. "The fact is Henry Brunson didn't do this, once the evidence started to come in, her story didn't match what the evidence was, it was clear there was some agenda."

Documents show the witness initially identified another possible shooter in the case. Witnesses in the car with Isaac that night also didn't mention another person in the car during their initial interviews, and an FDLE investigation revealed a second weapon was used in the shooting, which also contradicts the witness' statement.

WINK News spoke exclusively with Brunson's father, who says "if he wasn't innocent, they wouldn't have sent him home. I'm happy, now they need to find the right person."