1.  Generally

Several of the exceptions to the hearsay rule only apply where there is a showing that the declarant is unavailable to testify at trial.  See DYING DECLARATIONS; FAMILY; STATEMENTS AGAINST INTEREST; TESTIMONY.

2.  Circumstances Constituting Unavailability

"Unavailability" can mean anything from a witness’ death{footnote}FRE 804(a)(4).{/footnote} to a witness’ unwillingness or inability{footnote}FRE 804(a)(4).

 But see People v. Johnson, 118 Ill. 2d 501, 517 N.E.2d 1070 (1987) (child witness too intimidated to testify in court not deemed unavailable for purpose of introducing videotaped testimony.{/footnote} to testify even though on the stand and under oath.{footnote}See generally Cal. § 240.  {/footnote}  Circumstances which have been deemed to satisfy the "unavailability" requirement include various types of physical illness{footnote}Mutuelles Unies v. Kroll & Linstrom, 957 F.2d 707 (9th Cir. 1992)(witness "unavailable" who became ill during trial and required surgery).{/footnote} or mental illness or disability,{footnote}[cases]

But see Dear v. Chicago Transit Authority, 72 Ill. App. 3d 729, 391 N.E.2d 119 (1st Dist. 1979)(witness temporarily ill with flu deemed available to testify).{/footnote} inability of the witness to remember,{footnote} [4215]  FRE 804(3); United States v. Collins, 478 F.2d 837 (5th Cir. 1973) (G), {/footnote} refusal of the witness to testify and absence from the present proceedings.{footnote}FRE 804(a)(5). {/footnote} A witness who asserts a privilege to avoid testifying is deemed unavailable.{footnote} [4217]  FRE 804(a)(2); But see United States v. Mangan, 575 F.2d 32, 45 n.14 (2d Cir. 1978) (must be ruling that testimony is privileged).{/footnote}  This includes witnesses asserting their Fifth Amendment privilege against self-incrimination.{footnote} [4218]United States v. Bahadar, 954 F.2d 821, 828 (2d Cir. 1992); United States v. Taplin, 954 F.2d 1256, 1258 (6th Cir. 1992); United States v. Ramirez, 990 F.2d 1264 (9th Cir. 1993).{/footnote} That a witness is absent is not always sufficient to render that witness’ hearsay statements admissible.  The proponent must show that it diligently attempted to obtain the witness’ testimony but was unable to{footnote} [4219]  FRE 804(a)(5); Cal. § 240 (a)(5).  ; United States v. Hayes, 535 F.2d 479 (8th Cir. 1976); United States v. Guillette, 547 P.2d 743 (2d Cir. 1976); Kleeman v. Fragman Construction, 91 Ill. App. 3d 455, 414 N.E.2d 1064 (1st Dist. 1980)("perfunctory" attempts to locate witness held insufficient).{/footnote} because the witness was out of the jurisdiction,{footnote}Karris v. Woodstock, Inc., 19 Ill. App. 3d 1, 312 N.E.2d 426 (1st Dist. 1974), cert. denied, 420 U.S. 929.{/footnote} or could not be located after diligent effort, or failed to comply with a subpoena.{footnote}Kendor v. Dept. of Corrections, 126 Ill. App. 3d 648, 467 N.E.2d 1107 (1st Dist. 1984); Buckley v. Cronkhite, 74 Ill. App. 3d 487, 393 N.E.2d 60 (2d Dist. 1979) (failure to appear in response to subpoena despite agreement to do so).{/footnote}  Of course, a party cannot cause a witness to be unavailable to testify and thereby take advantage of this exception to the hearsay rule.{footnote} [4222]  FRE 804(a); Cal. § 240(b).{/footnote}  The fact that the witness cannot be called due to a limitation imposed by the trial judge on the number of witnesses does not satisfy the "unavailability" requirement.{footnote}Secretary of Labor v. DeSisto, 929 F.2d 789 (1st Cir. 1991).{/footnote}

In a criminal case, admission of prior testimony against the defendant raises the question of whether the defendant’s Confrontation Clause rights are being violated.  See CONFRONTATION.  It has been held that admission of such evidence is permissible where the defendant had an opportunity to cross-examine the witness at the prior proceeding and the witness is now "unavailable" despite the prosecution’s good faith efforts.{footnote} [4224]Barber v. Page, 390 U.S. 719, 725 (1968); California v. Green, 399 U.S. 149 (1970). 
            State v. Breeden, 634 A.2d 464 (Md. 1993).{/footnote}  In criminal cases, for example, the prosecution may be required to produce a witness who is incarcerated in another state if it is able to do so.{footnote}Barber v. Page, 390 U.S. 719 (1968).
{/footnote} 

3.  Attempt to Depose Required

Under the federal rules and in some states, the proponent of the hearsay must have at least attempted to depose the witness if the witness can be located.{footnote} [4226]  FRE 804(a)(5); Burton v. Oldfield, 79 S.E.2d 660 (Va. 1954).  {/footnote} 

§ 3(a).  Exception for Prior Testimony. 

Where the hearsay being offered is itself prior testimony, a deposition requirement would be superflous.  Thus, prior testimony which is otherwise admissible as hearsay (see TESTIMONY) will not be excluded simply because the proponent did not attempt to take the declarant’s deposition.{footnote}FRE 804(a)(5).{/footnote} 

4.  Burden of Proof

The proponent of the evidence at issue bears the burden of proving the declarant’s unavailability.{footnote}Kirk v. Raymark Industries, Inc., 61 F.3d 147 (3d Cir. 1995), cert. denied, 116 S.Ct. 1015, 134 L.Ed.2d 95.{/footnote}