Alternative (a bit longer): suėmimo arba šaukimo atvykti į policiją ar teismą numeris. The definition in English is as follows: The Arrest Summons Number (ASN) is generated by the PNC for every arrest or summons that occurs. The ASN identifies a specific individual arrested or summonsed for a specific case; it is a unique identifier and the principle means of identifying a defendant within a case. / http://tinyurl.com/64s3qwy

Vietoje arešto šiuo atveju geriau naudoti suėmimą, nes areštuoti galima ne tik asmenį, bet ir turtą (turto areštas).

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Note added at 1 day22 hrs (2011-02-22 05:52:39 GMT)
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You may consider to use just "suėmimo numeris", which in principal will be clear enough in Lithuanian text.