Association of Firearm & Tool Mark Examiners Puerto Rico Crime Lab

An armed robbery took place in San Juan Puerto Rico. A number of fired 9mm cartridge cases were recovered at the scene. Some of these were allegedly linked to the guns of several suspects arrested shortly after the robbery. A number of the 9mm cartridge cases from the scene could not be matched to any of the firearms recovered from the suspects in custody. Some days after the robbery, defendant David Morales Machuca was arrested by the FBI, and found to be in possession of a Taurus PT92 9mm pistol.

Mr Machuca never denied that he was the owner of the Taurus pistol - note that he was committing a criminal offence by possessing it (PR has unusually strict firearms laws but, apparently, a high incidence of firearms crime).

Mr Machuca's Taurus pistol was sent to the Puerto Rico Crime Lab in San Juan, where it was examined and test fired by Association of Firearm and Tool Mark Examiners (AFTE) member, Carmen Suliveras Ortiz - henceforth referred to as Ms Suliveras. Ms Sulliveras has a bachelors Degree in Chemistry, and a Masters Degree in Public Affairs. Ms Suliveras proudly boasted that every firearms examiner in the Puerto Rico Crime Lab was a member of the Association of Firearm & Tool Mark Examiners (AFTE).

Ms Suliveras took the empty cartridge cases that she had fired in Mr Machuca's Taurus pistol, and compared them to the remaining unidentified cartridge cases from the armed robbery. Eureka ! a match was declared, and Mr Machuca was charged with being a part of the armed robbery.

Thus far, all sounds well, but Mr Machuca's attorney, exercising due diligence, hired an independent consultant, from the US mainland, to make a comparison of the cartridge cases from the scene, and those test fired in Mr Machuca's Taurus 9mm pistol. The results of the independent examination proved that there was no way that the cartridge cases from the scene were fired in Mr Machuca's pistol (see images below). This was confirmed by a second independent consultant from the US mainland. The prosecution reportedly sent the evidence back to the Puerto Rican crime lab, where it was re-evaluated by the Firearms Section Supervisor (another AFTE member) who confirmed Ms Suliveras' opinion that this was indeed a definite match.

Ms Suliveras subsequently testified in court, stating that she was absolutely certain that the cartridge cases from the scene were fired from Mr Machuca's Taurus pistol - they were definitely a match in her esteemed opinion. Despite testimony to the contrary from the Defense expert, the PR jury ultimately chose to believe the local PR prosecution witness.

When confronted with photomicrographs illustrating the marked differences between the fired cases from the scene, and the fired cases from Mr Machuca's Taurus, Ms Suliveras responded by saying that when a human looks through a microscope they see a 3D image, whereas the camera records a 2D image, hence the apparent photographic differences between the scene exhibits and the cartridge cases fired in Mr Machuca's Taurus. Anyone reading the previous sentence who has any experience of microscopy, optics, and/or photography is probably crying with laughter right now !

Mr Machuca was found guilty, and subsequently sentenced to life plus 60 years, effectively ending this young man's life.

Without the damning testimony of Ms Suliveras, Mr Machuca may have been found not guilty of the charges against him. Even if he were guilty, we must ask the question, is it acceptable to use bogus evidence to secure a conviction ?

Even though this incident occurred in San Juan, Puerto Rico, it was in a US Federal Court - a venue that is supposed to set an example to the rest of the World when it comes to fair, even handed justice.

Look at the evidence pictures below and make your own judgement - was this just outright incompetence, blatant perjury, or a combination of the two ?


A 9mm cartridge case fired in Mr Machuca's Taurus (left) compared to Exhibit 7 (E3) from the robbery scene (anyone out there see a match here ?) This is a view looking at the rear of the cartridge case. The round part in the middle is the primer - the component that, when struck by the firing pin of the firearm, ignites the propellant in the cartridge case. For the uninitiated, the indentation near the center is from the firing pin of the firearm, and the raised area around the indentation, and the marks on the rest of the primer, are produced by imperfections on the breech face of the pistol. It is the uniqueness of these imperfections (in both the firing pin indentation and the breech face marks) that can lead to a fired cartridge being identified as being fired in a given (suspect firearm). The photomicrographs (photographs taken through a microscope) below illustrate how each of the cartridge cases from the scene match one another, and how each of the cartridge cases fired in Mr Machuca's pistol match one another, then finally, a direct microscopic comparison of a cartridge case from the scene to one fired from Mr Machuca's pistol. If anyone can see a match in this third set of pictures, then please send an email (perhaps this aspect of cartridge case comparison was the subject of an AFTE seminar at some time ?) Enjoy the Show


Exhibit 7 E2 from Robbery Scene	Exhibit 7 E8 from Robbery Scene


Exhibit 7 E2 from Robbery Scene (primer close-up)	Exhibit 7 E8 from Robbery Scene (primer close-up)


Exhibit 7 E2 from Robbery Scene (firing pin indentation close-up)	Exhibit 7 E8 from Robbery Scene (firing pin indentation close-up)
The above cartridge cases were clearly fired in the same firearm - as evidenced by the large number of repeatable individual characteristics


Cartridge Case Fired in Mr Machuca's Taurus	Exhibit 7 E8 from Robbery Scene


Cartridge Case Fired in Mr Machuca's Taurus (primer close-up)	Exhibit 7 E8 from Robbery Scene (primer close-up)


Cartridge Case Fired in Mr Machuca's Taurus (firing pin indentation close-up)	Exhibit 7 E8 from Robbery Scene (firing pin indentation close-up)

Is anyone seeing the match here ? If not, then perhaps it's time to contact the media, your Congressman, Senator, or even Supreme Court Chief Justice John G Roberts Jr - if you just sit back and let this slide, then the US justice system will end up as something that Saddam Hussein would be proud of.