Ollie'sPolice Handbook
All procedures
Road Traffic

MGDD — Drink-Drive Station Procedure

The evidential breath/blood/urine procedure at the station after a positive roadside test or s.4 unfit arrest. Run the MGDD/A booklet — any deviation can collapse the case at court.

The steps

  1. 1

    1. Arrival & custody

    Book the suspect in. Custody officer authorises detention under PACE s.37 to obtain evidential specimens (s.7 RTA 1988).

  2. 2

    2. Open MGDD/A

    Use the current MGDD/A booklet on a Lion Intoxilyzer / Camic / Intoximeter EC/IR. Verify the device is in calibration (cal check log).

  3. 3

    3. Statutory warning

    Read verbatim: "I require you to provide two specimens of breath for analysis. The lower of the two readings will be used. Failure to provide a specimen when required may render you liable to prosecution."

  4. 4

    4. Two evidential breath samples

    Take two specimens at least 3 minutes apart. The lower reading is the evidential one. Print and exhibit both printouts (e.g. AB/01).

  5. 5

    5. Statutory option (≤ 50 µg)

    If the lower reading is 40–50 µg/100ml breath, offer the statutory option to replace breath with blood or urine (officer's choice of which). Record the offer and reply.

  6. 6

    6. Blood / urine where required

    If breath is unreliable / medical reason / statutory option taken — call FME or HCP for blood, or take 2 urine samples within 1 hour (first sample discarded). Use sealed kits, divided sample to suspect.

  7. 7

    7. Charge or release

    Above the limit and case file complete → charge (with bail conditions / disqualification interim). Below the limit → release no further action and return licence/keys.

Related Acts & sections

RTA 1988
s.4 Unfit

Driving, attempting to drive, or being in charge of a mechanically propelled vehicle on a road or other public place when unfit to drive through drink or drugs (i.e. ability impaired).

RTA 1988
s.5 Excess Alcohol

Driving, attempting to drive, or being in charge of a motor vehicle on a road/public place after consuming alcohol over the prescribed limit.

RTA 1988
s.6 Roadside Tests

Power for a constable to require a preliminary breath test, preliminary impairment test, or preliminary drug test where one of the statutory triggers is met.

Watch outs

  • Failure to provide without reasonable excuse is itself an offence (s.7(6)) — same penalty as drink-drive.
  • Medical reason for not providing breath must be assessed by an HCP, not the officer.
  • Do NOT 'top up' or repeat the warning to coerce — court will exclude.

References