Lisa Johnson was arrested on July 9, 1993, and posted bond and was released from custody on July 21, 1993. In September of 1993, the City of Atlanta Bond Administrator closed the bonding company used by Ms. Johnson because of unpaid outstanding judgments. The grand jury indicted Ms. Johnson on December 10, 1993 for malice murder, felony murder, and aggravated assault. She failed to appear at her scheduled arraignment on January 18, 1994, and a bench warrant was issued on January 31. On June 16, 1994, the trial court entered a judgment against the bonding company for its failure to have Ms. Johnson appear. On November 18, 1999, the criminal case was assigned to the backlog calendar, and an investigator quickly discovered that Ms. Johnson was living with her mother in Kansas City, Missouri. After extradition, the trial court set bond and again *512released Ms. Johnson from custody on December 22, 1999. The case appeared on several plea and arraignment calendars throughout the year 2000 and, on September 25, Ms. Johnson filed a plea in bar based upon an alleged violation of her constitutional right to a speedy trial. The trial court sustained that plea, and the State appeals.
The sole issue is whether the trial court abused its discretion in balancing the four factors set forth in Barker v. Wingo, 407 U. S. 514 (92 SC 2182, 33 LE2d 101) (1972) and finding a violation of the constitutional right to a speedy trial in this case. Torres v. State, 270 Ga. 79, 81 (2) (508 SE2d 171) (1998). Those four factors are “(1) the length of the delay; (2) the reason for the delay and whether this is attributable to the defendant or the state; (3) the timeliness of the defendant’s assertion of the right to a speedy trial; and (4) prejudice to the defendant.” Jackson v. State, 272 Ga. 782, 783 (534 SE2d 796) (2000). “ ‘These factors have no talismanic qualities; courts must still engage in a difficult and sensitive balancing process.’ [Cit.]” Brown v. State, 264 Ga. 803, 805 (2) (450 SE2d 821) (1994). “Absent an abuse of discretion, the decision of the trial court must be affirmed. [Cit.]” Snow v. State, 229 Ga. App. 532, 533 (494 SE2d 309) (1997).
1. The extraordinary delay of about seven years from arrest and indictment to trial is more than sufficient to raise a threshold presumption of prejudice and require analysis of the remaining three factors. Doggett v. United States, 505 U. S. 647, 652 (II) (112 SC 2686, 120 LE2d 520) (1992); Barker v. Wingo, supra at 533-534 (V); Nelloms v. State, 274 Ga. 179 (549 SE2d 381) (2001); Johnson v. State, 268 Ga. 416, 417 (2) (490 SE2d 91) (1997).
The delay is then considered a second time by factoring it into the prejudice prong of the Barker analysis, with “the presumption that pretrial delay has prejudiced the accused intensifying) over time.” [Cits.] . . . “[I]t is part of the mix of relevant facts, and its importance increases with the length of delay.” [Cit.]
Boseman v. State, 263 Ga. 730, 732 (1) (a) (438 SE2d 626) (1994). See also Doggett v. United States, supra at 652 (II), 656 (III) (A).
2. The trial court found that each party was partially responsible for the delay. The transcript contains evidence that, in 1993, Ms. Johnson gave the court and the bonding company her Atlanta address, but then left with her mother for Missouri as soon as she was released, and never informed the clerk’s office of her new address. However, other evidence indicates that Ms. Johnson gave the police department her mother’s address. Indeed, police department records enabled the investigator to locate Ms. Johnson quickly *513in 1999. The closing of the bonding company was a neutral factor, but the State concedes that an overcrowded court docket and understaffed law enforcement offices are additional reasons for the delay. While such matters weigh less heavily against the State than intentional delay, they nevertheless must be considered since the ultimate responsibility for their existence rests with the government rather than with the defendant. Strunk v. United States, 412 U. S. 434, 436 (I) (93 SC 2260, 37 LE2d 56) (1973); Barker v. Wingo, supra at 531; Lett v. State, 164 Ga. App. 584, 585 (2) (298 SE2d 541) (1982). “The state’s negligence ‘still falls on the wrong side of the divide between acceptable and unacceptable reasons for delaying a criminal prosecution once it has begun.’ [Cit.]” Jackson v. State, supra at 782-783. Furthermore, those delays during 2000 which were attributable to the prosecutor’s lack of preparation must also be considered the result of the State’s negligence. Johnson v. State, supra at 418 (2). Therefore, the trial court was authorized to find that at least part of the blame for the seven-year delay rests with the State.
3. Ms. Johnson states that she filed a demand for trial on December 22, 1999, only twelve days after learning of the indictment. However, the document to which she refers is simply a demand for a jury trial and does not invoke either a constitutional or statutory right to a speedy trial. Getz v. State, 251 Ga. 462 (306 SE2d 918) (1983); Boyd v. State, 200 Ga. App. 591 (2) (409 SE2d 44) (1991). Ms. Johnson actually asserted her Sixth Amendment right to a speedy trial on September 25, 2000, shortly before trial was scheduled. Consistent with the ruling of the trial court* however, this delay in invoking her rights weighs no more than slightly against her, because six years of the delay was at least in part attributable to the State and she was unaware of the indictment during that time. See Doggett v. United States, supra at 653-654 (II).
4. In analyzing the prejudice factor, we “consider three interests: (i) preventing oppressive pretrial incarceration, (ii) minimizing anxiety and concern of the defendant, and (iii) limiting the possibility that the defense will be impaired.” Brannen v. State, 274 Ga. 454, 456 (553 SE2d 813) (2001). “Of these forms of prejudice, ‘the most serious is the last, because the inability of a defendant adequately to prepare his case skews the fairness of the entire system.’ [Cit.]” Doggett v. United States, supra at 654 (III) (A). See also Barker v. Wingo, supra at 532 (IV); Nelloms v. State, supra at 181. Indeed, the trial court found, as it was authorized to do, that the incarceration lasted only a few weeks and did not involve any mistreatment, and that the pending charges did not produce any unusual anxiety and concern on the part of Ms. Johnson. Brannen v. State, supra at 457.
As for impairment of the defense, the State cannot account for an audiotape recording which allegedly contains three phone calls to *514911 made by Ms. Johnson begging for help just before she stabbed the victim. The State erroneously contends that defense counsel lost the 911 tape and that the trial court found no evidence that the State ever possessed the tape. To the contrary, there was evidence that the State possessed the original 911 tape and that defense counsel only lost a copy of the tape. Compare Nairon v. State, 215 Ga. App. 76, 77 (1) (d) (449 SE2d 634) (1994); Ould v. State, 186 Ga. App. 55, 57 (2) (d) (366 SE2d 392) (1988). In its ruling, the trial court never found that the State did not possess the tape, but rather recognized the conflict in the evidence and observed that the defense is not usually in possession of such an original tape and that Johnson presented evidence that the tape lost by defense counsel was a copy. It appears that self-defense is the key issue in this case and that the tape would be highly relevant as an audio recording of the actual homicide with which Ms. Johnson is charged. The loss of such evidence is analogous to the death or disappearance of witnesses, where “the prejudice is obvious.” Barker v. Wingo, supra at 532 (XV). See also Brannen v. State, supra at 457; State v. Yates, 223 Ga. App. 403, 404 (477 SE2d 670) (1996). The State relies on the fact that several witnesses listened to the tape before its loss and can testify as to its contents. At the hearing on the plea in bar, however, there were considerable inconsistencies between the testimony of prosecution witnesses and that of defense witnesses regarding the contents of the missing 911 tape. Because there has not been any stipulation as to the tape’s contents or any agreement that only defense testimony regarding those contents would be admissible at trial, the prejudice to the defendant from the loss of the evidence has not been “alleviated,” as it was in Brannen v. State, supra at 458, and Nelloms v. State, supra at 181.
The trial court was primarily concerned about the seven-year delay and the loss of evidence which was potentially very helpful to the defense.
[T]he Supreme Court [of the United States] in Doggett held that “consideration of prejudice is not limited to the specifically demonstrable.” [Cit.] The Court held that the presumption of prejudice that arises from the passage of time strengthens with the length of the delay and may tilt the prejudice factor in a defendant’s favor, although it may not alone carry a Sixth Amendment claim without regard to the other Barker criteria. [Cit.]
Boseman v. State, supra at 734 (1) (d). Because there were conflicts in the evidence, particularly as to the contents of the 911 tape and the reasons for the extraordinary delay here, we cannot undertake a de novo appellate review of the difficult decision with which the trial *515court struggled in this case. Compare Snow v. State, supra at 532. In light of all of the evidence and the trial court’s findings, especially with regard to the unusually long delay and the loss of potentially critical evidence, we conclude that the trial court, in applying the balancing test first set forth in Barker, did not abuse its discretion in sustaining the plea in bar filed by Ms. Johnson. See Doggett v. United States, supra; State v. Yates, supra at 404.
Judgment affirmed.
All the Justices concur, except Benham and Thompson, JJ, who dissent.