The Court continued in relevant part: Upon returning to police headquarters, Muller placed the sealed box containing the vials of defendant’s blood inside a refrigerator outfitted with specially-designed locked boxes. He removed the key, depositing it through a hole accessible only by the on-duty detective.
The morning after the blood was drawn, Detective Crescitelli removed the blood sample from the secured refrigerated locker and transported it to the New Jersey State Police lab where he turned it over to a lab technician. During the thirty-four-minute ride from police headquarters to the State Police laboratory in Hammonton, the blood sample remained on the seat of the car next to Crescitelli.
Michelle Adamson, a chemist employed by the State Police laboratory in Hammonton, testified that she tested defendant’s blood sample using the head space gas chromatography test. After retrieving the sample from the vault, Adamson took it to the toxicology unit and affixed bar-coded labels to the tubes. Applying the procedures that she was trained to use after having been certified as an expert in head space gas chromatography testing, Adamson tested two samples of defendant’s blood. She testified that she followed the standard procedure of adding a specified and known concentration of n-propenyl to the blood sample. She explained that the machine then calculates a peak for both the ethanol in the blood and the additive n-propenyl and determines the ratio of the area of the ethanol compared to the area occupied by the n-propenyl standard. That computation results in a peak area ratio. It is the peak area ratio that is then used to determine the quantity of alcohol in the blood. Using those procedures, Adamson testified that defendant’s blood alcohol content (BAC) was 0.1416 on vial A and 0.1403 on vial B.
The testimony regarding the location of the samples from the time that it was drawn until it was tested relates to “chain of custody.” Chain of custody relates to the weight of the evidence. If there are custodial time gaps between the receipt of a sample and its testing, the defense can argue that the sample may have been tampered with and/or that the results are otherwise unreliable.
