In this landmark judgment, Apex Court held that Right to speedy trial is implicit to Article 21 of Constitution of India and also passed guidelines to ensure that this right is not violated, and it violated, Constitutional Courts have a duty to fix such violation appropriately.

From Para 14,

14. Time and again this Court has emphasized the need for speedy investigations and trial as both are mandated by the letter and spirit of the provisions of the CrPC. (In particular, Sections 197, 173, 309, 437 (6) and 468 etc.) and the constitutional protection enshrined in Article 21 of the Constitution. Inspired by the broad sweep and content of Article 21 as interpreted by a seven-Judge Bench of this Court in Maneka Gandhi Vs. Union of India & Anr., in Hussainara Khatoon & Ors. Vs. Home Secretary, State of Bihar, this Court had said that Article 21 confers a fundamental right on every person not to be deprived of his life or liberty except according to procedure established by law; that such procedure is not some semblance of a procedure but the procedure should be ‘reasonable, fair and just’; and therefrom flows, without doubt, the right to speedy trial. It was also observed that no procedure which does not ensure a reasonably quick trial can be regarded as ‘reasonable, fair or just’ and it would fall foul of Article 21. The Court clarified that speedy trial means reasonably expeditious trial which is an integral and essential part of the fundamental right to life and liberty enshrined in Article 21.

From Para 15,

15. The exposition of Article 21 in Hussainara Khatoon’s case (supra) was exhaustively considered afresh by the Constitution Bench in Abdul Rehman Antulay & Ors. Vs. R.S. Nayak & Anr.11. Referring to a number of decisions of this Court and the American precedents on the Sixth Amendment of their Constitution, making the right to a speedy and public trial a constitutional guarantee, the Court formulated as many as eleven propositions with a note of caution that these were not exhaustive and were meant only to serve as guidelines. For the sake of brevity, we do not propose to reproduce all the said propositions and it would suffice to note the gist thereof. These are:
(i) fair, just and reasonable procedure implicit in Article 21 of the Constitution creates a right in the accused to be tried speedily;
(ii) right to speedy trial flowing from Article 21 encompasses all the stages, namely the stage of investigation, inquiry, trial, appeal, revision and retrial;
(iii) in every case where the speedy trial is alleged to have been infringed, the first question to be put and answered is —
who is responsible for the delay?;
(iv) while determining whether undue delay has occurred (resulting in violation of right to speedy trial) one must have regard to all the attendant circumstances, including nature of offence, number of accused and witnesses, the work-load of the court concerned, prevailing local conditions and so on— what is called, the systemic delays;
(v) each and every delay does not necessarily prejudice the accused. Some delays may indeed work to his advantage. However, inordinately long delay may be taken as presumptive proof of prejudice. In this context, the fact of incarceration of accused will also be a relevant fact. The prosecution should not be allowed to become a persecution. But when does the prosecution become persecution, again depends upon the facts of a given case;
(vi) ultimately, the court has to balance and weigh several relevant factors—’balancing test’ or ‘balancing process’—and determine in each case whether the right to speedy trial has been denied;
(vii) Ordinarily speaking, where the court comes to the conclusion that right to speedy trial of an accused has been infringed the charges or the conviction, as the case may be, shall be quashed. But this is not the only course open and having regard to the nature of offence and other circumstances when the court feels that quashing of proceedings cannot be in the interest of justice, it is open to the court to make appropriate orders, including fixing the period for completion of trial;
(viii) it is neither advisable nor feasible to prescribe any outer time-limit for conclusion of all criminal proceedings. In every case of complaint of denial of right to speedy trial, it is primarily for the prosecution to justify and explain the delay. At the same time, it is the duty of the court to weigh all the circumstances of a given case before pronouncing upon the complaint;
(ix) an objection based on denial of right to speedy trial and for relief on that account, should first be addressed to the High Court. Even if the High Court entertains such a plea, ordinarily it should not stay the proceedings, except in a case of grave and exceptional nature. Such proceedings in High Court must, however, be disposed of on a priority basis.

From Para 17,

17. It is, therefore, well settled that the right to speedy trial in all criminal persecutions is an inalienable right under Article 21 of the Constitution. This right is applicable not only to the actual proceedings in court but also includes within its sweep the preceding police investigations as well. The right to speedy trial extends equally to all criminal persecutions and is not confined to any particular category of cases. In every case, where the right to speedy trial is alleged to have been infringed, the court has to perform the balancing act upon taking into consideration all the attendant circumstances, enumerated above, and determine in each case whether the right to speedy trial has been denied in a given case. Where the court comes to the conclusion that the right to speedy trial of an accused has been infringed, the charges or the conviction, as the case may be, may be quashed unless the court feels that having regard to the nature of offence and other relevant circumstances, quashing of proceedings may not be in the interest of justice. In such a situation, it is open to the court to make an appropriate order as it may deem just and equitable including fixation of time for conclusion of trial.

Citations : [2008 RCR CRI 4 890], [2008 AIR SC 0 5165], [2008 JT 8 109], [2008 AIR SC 3077], [2008 RAJ 6 293], [2008 SCC 16 117], [2008 WLC 2 677], [2008 MLJ CRI 2 1649], [2009 SCJ 1 998], [2008 SCALE 9 760], [2008 CCR 3 176], [2008 DLT CRI 3 533], [2008 SLT 6 233], [2008 AIOL 2116], [2008 ANJ SC 2 173], [2008 BOMCR CRI SC 2 590], [2010 SCC CRI 4 217], [2008 AIC SC 68 93], [2009 LLN 2 798], [2009 FLR 122 790], [2008 CRLJ SC 3944], [2008 AIR SCW 5165]

Other Sources:

https://indiankanoon.org/doc/1223002/

https://www.casemine.com/judgement/in/5609ae6ae4b0149711413c8f