Directorate of Forensic Science LaboratoriesGovernment of Maharashtra

Technology evolution

What has changed at the bench

Older reports remain valid records of what was done at the time. These timelines show what the laboratory would add today, so an old finding is read in the right light.

DNA profiling

Maharashtra laboratories moved from blood grouping and early multiplex kits to expanded STR panels with automated extraction and quantification.

  1. Up to 2010Blood grouping and early RFLP work
    Superseded

    Association was mostly at class level through ABO grouping and absorption-elution. Individualisation was rarely possible and casework often stopped at species and group.

  2. 2010 to 2016AmpFlSTR Identifiler and Identifiler Plus
    Superseded

    Fifteen autosomal loci plus Amelogenin on ABI 3130xl platforms. Adequate for clean reference comparisons but thin on degraded or mixed material.

  3. 2016 to 2021PowerPlex 21 and mini-STR supplements
    Still accepted

    Twenty autosomal loci with better tolerance for inhibition. Mini-STR markers were added for degraded bone and tissue.

  4. 2021 onwardsExpanded kits, automation and probabilistic mixture work
    Current practice

    GlobalFiler class kits with 24 markers, automated extraction, Real-Time PCR quantification with degradation indices, and structured mixture interpretation. Current laboratory practice for fresh and challenged samples.

Toxicology

Screening has shifted from colour tests and TLC alone to instrument confirmation with quantification, which matters for weight in court.

  1. Up to 2012Colour tests and thin layer chromatography
    Superseded

    Useful for screening but not sufficient on their own for a confirmed identification of a specific compound.

  2. 2012 to 2018GC and GC-MS confirmation
    Still accepted

    Gas chromatography with mass spectrometry became the confirmation standard for pesticides, alkaloids and volatiles.

  3. 2018 onwardsLC-MS/MS with quantification
    Current practice

    Liquid chromatography tandem mass spectrometry with calibrated quantification, plus AAS for heavy metals. Quantitative values are now expected wherever the matrix allows.

Ballistics and firearm discharge residue

Comparison microscopy remains the backbone, now supported by instrumental residue analysis and image documentation.

  1. Up to 2014Comparison microscopy with chemical residue tests
    Still accepted

    Firing pin, breech face and striation comparison with Walker's test or modified Griess test for nitrite. Documentation was largely descriptive.

  2. 2014 to 2020Digital imaging and SEM-EDX for residue
    Still accepted

    Photomicrograph documentation of matching striations along with scanning electron microscopy and energy dispersive X-ray for particle level residue.

  3. 2020 onwardsInstrumented residue analysis with documented comparison sets
    Current practice

    SEM-EDX for characteristic lead, barium and antimony particles, ICP-MS where trace levels matter, and stored digital comparison images that can be re-examined.

Digital and cyber forensics

Tooling changes fast. The extraction method and tool version decide what can be recovered, so both belong in every report.

  1. Up to 2015Manual examination and early imaging tools
    Superseded

    Photographs of screens, logical copies and limited deleted data recovery. Hashing was inconsistent across cases.

  2. 2015 to 2021Cellebrite UFED and Magnet AXIOM workflows
    Still accepted

    Physical and file system extraction with hash values recorded before and after examination, plus structured application parsing.

  3. 2021 onwardsCurrent suite with cloud and encrypted app support
    Current practice

    Later Cellebrite and AXIOM releases with full file system and keychain acquisition, cloud token handling, and Section 65B compliant certificates generated alongside the extraction.

Serology and biology

Serology is now a screening step that feeds DNA work rather than a stand-alone conclusion.

  1. Up to 2012Benzidine, Takayama and ABO grouping
    Superseded

    Benzidine was later withdrawn from routine use on health grounds. Grouping gave class level association only.

  2. 2012 to 2018Phenolphthalein screening with precipitin species tests
    Still accepted

    Safer presumptive chemistry with anti-human precipitin for species origin, followed by referral for DNA where individualisation was needed.

  3. 2018 onwardsRapid immunochromatographic screening feeding STR profiling
    Current practice

    Card based tests for blood, semen and saliva, followed by STR profiling on the same stain so the conclusion reaches individual level.

Method status at a glance

  • AmpFlSTR Identifiler Plus
    Superseded

    Standard until roughly 2016. Current practice: Expanded STR kits of the GlobalFiler class with automated extraction and Real-Time PCR quantification..

  • PowerPlex 21 System
    Still accepted

    Standard until roughly 2021. Current practice: Expanded 24 marker kits with degradation indices, retained for casework continuity where the earlier profile must be compared directly..

  • ABO grouping by absorption-elution
    Superseded

    Standard until roughly 2012. Current practice: Presumptive screening followed by STR profiling of the same stain for individual level association..

  • Benzidine test
    Superseded

    Standard until roughly 2012. Current practice: Phenolphthalein or card based immunochromatographic screening..

  • Takayama test
    Still accepted

    Standard until roughly 2015. Current practice: Confirmatory immunological tests with DNA referral for the same stain..

  • Colour tests and thin layer chromatography alone
    Superseded

    Standard until roughly 2012. Current practice: Screening followed by GC-MS or LC-MS/MS confirmation with quantification wherever the matrix allows..

  • Walker's test / modified Griess test
    Still accepted

    Standard until roughly 2018 as a stand-alone residue finding. Current practice: SEM-EDX for characteristic lead, barium and antimony particles, supported by the chemical test as a screen..

  • Cellebrite UFED 4PC
    Still accepted

    Standard until roughly 2021 for encrypted application data. Current practice: Current Cellebrite and Magnet releases with full file system acquisition, cloud token handling and a Section 65B certificate issued with the extraction..

  • Immunoassay screening without confirmation
    Superseded

    Standard until roughly 2015. Current practice: Immunoassay used only as a screen, with LC-MS/MS confirmation before reporting..