The Prosecutor, November-December 2012, Volume 42, No. 6

Evidence 101

A guide to admitting evidence at trial

You’ve picked a sympathetic jury, given a moving opening statement, and now you’re ready to offer up all kinds of incriminating stuff against the defendant. Everything is golden … until there’s an objection to your evidence. The judge asks you for a response. Sweat beads up on your furrowed brow. You fan yourself with your extremely well-written and expertly edited copy of Family Violence Investigation and Prosecution, thoughts of its witty and attractive authors (ahem) doing nothing to calm your nerves.
    You look to your co-counsel—listlessly thumbing through the case file, blind to your plight. You look to the defense attorney—cackling madly, twirling a devilish mustachio. You look to the judge—shooting a death-gaze, impatiently waiting to keep your evidence out. You’re the conductor of a case careening off the rails into a burning chasm of doom where your boss waits to fire you for incompetence, leaving you a penniless shill doing document review or *gasp* criminal defense. What do you do?! Pull the brake! And read on.

The basics
Stop, relax, take a deep breath, and repeat after me: Admitting evidence is easy. It probably doesn’t seem like it, but let’s look at the core standard for getting anything in, Rule 901. It simply says that the foundation for admitting evidence “is satisfied by evidence sufficient to support a finding that the matter in question is what its proponent claims.”1 In other words, you just have to convince the judge that whatever you’re offering is what you say it is. Even where predicates are suggested by the rules, they’re just for “illustration only, and not by way of limitation, [merely] examples.”2 There are no magic words for admitting evidence.
    So when you respond to an objection about evidence, don’t get twisted up in technicalities. Just explain to the judge why the evidence is authentic—how you know it’s the same piece of evidence collected on-scene and why you’re sure it hasn’t been altered. And if the defense keeps on objecting, remember that they have to be specific about what part of the predicate they believe is lacking.3 Once you insist on that, you may discover that they don’t have a good reason for keeping something out, or more commonly, that their objections go to the weight of the evidence and not its admissibility (which is a handy response you can give in these situations).

The mechanics
So how does that translate into practical action? Well, let’s start with something so incredibly simple that they often don’t teach it in law school: what to do in mechanical terms. Start by marking your exhibit with a number, letter, or whatever symbol is used in your jurisdiction so it’s identified for the record. Before offering a piece of evidence or talking to a witness about it to lay the foundation, show it to the defense lawyer and make sure the record reflects that you did so (“I’m showing defense counsel what I’ve marked as State’s Exhibit Three”). If you need to give it to a witness to refer to as you go through your predicate questions, get the judge’s permission to approach the witness before handing it to the witness. Then just ask the questions and move to admit it.

There are some standard things to ask most witnesses that cover qualifications and connections. Anytime you’re questioning someone with specialized knowledge who’s going to sponsor a piece of evidence, you want to discuss how he knows what he knows. For example, when talking to a police officer, go over where he works and how long he’s been there, any relevant prior employment, what education, training, and experience he’s had, what ranks and certifications he holds, what his current assignment is, and so forth. You don’t want his life story, but make sure the jurors know whom they’re dealing with.
    What I mean by connections is showing how the evidence is linked to the case. Sometimes that’s as easy as pointing out whomever something needs to be connected to, such as who gave a breath sample in a DWI case:
Q.    You said “the defendant.” Can you point out whom you mean and describe what he’s wearing?
A.    He’s right there by the defense attorney and he’s wearing a blue shirt.
Q.    All right, let the record reflect that the witness has identified the defendant.

It might also involve describing the distinct characteristics4 of something to show from where or whom it came. That’s essential for things such as texts, emails, and social media messages, where you need to explore how the content or context of a message sheds light on who wrote it.5       
Q.    This is what’s been marked State’s Exhibit One; do you know what it is?
A.    Yes—it’s a copy of a text message that the defendant sent me that night.
Q.    How do you know it was from him?
A.    It came from his phone number. I got lots of texts from him when we dated, so I know how he writes, and this sounds like him. I also got this about an hour after he beat me up and that’s what we’re talking about in the message.
Q.    Is this printout the exact same message you got that night?
A.    Yes.
    Other than that, just be sure not to let the jury see anything before it’s admitted or else you’ll risk a mistrial. But once you’ve gotten something into evidence, go ahead and ask the judge for permission to show it to the jury, which is known as “publishing” it. As far as how to do that, always ask how to make the strongest impact on the jury with a particular piece of evidence. Jurors need to know exactly what it is, what it means, and why that’s important—they need to care about it. Also, if the jury is examining evidence, stop talking to the witness until the jurors are done; you don’t want their attention divided.

The theory
Now comes the exciting part: what to ask to get in your evidence.

Photographs and videos   
Prosecutors often think of photographs as the easiest type of evidence to admit, so that’s a good starting point:6
Q.    I’m showing you what I’ve marked State’s Exhibit One. What is it?
A.    It’s a picture of Jane Doe.
Q.    Does it accurately show how she looked that night?
A.    Yes.
    But let’s take a step back: Why is that the predicate for a photo? Because it establishes that the picture shows what you say it shows through a witness with personal knowledge7 of the subject matter. The defense may make a big deal about who took the photo or how clear the picture is, but all of that goes to the weight of the evidence, not whether it comes in.
    In principle, every piece of evidence is just as simple. Testimony of a witness with knowledge is the predicate for virtually everything. Although you may need to ask a few more questions, what it always comes down to is someone knowing about a thing and explaining the what, why, and how of it. Don’t fall into the trap of thinking about an arbitrary set of questions as the predicate for a kind of evidence; that’s a completely backwards approach that won’t teach you anything. If instead you take what we cover in this article as a general theory for admitting things, you can build questions for anything from it.
    In fact, the only additional tools you need are for specialized pieces that require a business records foundation, a chain of custody, or expert testimony. “Business records” are a broad category that covers documentation of any regularly conducted activity,8 including medical treatment. Usually they’re brought in through a custodian of records, but the rules specify “the custodian or other qualified witness” so you also can introduce medical records through a nurse or maintenance logs through a mechanic. What you have to show is simple: that the records were 1) created near the time the documented event happened; 2) kept regularly; 3) as part of the regular practice of the business; and 4) by or based on information from someone with personal knowledge of the event.

9-1-1 calls and computer-­aided dispatch (CAD) notes   
Combining what we’ve covered so far—qualifications, connections, testimony of a witness with knowledge, and a business records predicate—let’s look at getting in an emergency call recording:9
Q.    Good morning. Please tell the jury what you do for a living.
A.    I’m the custodian of records for El Paso Police Department communications.
Q.    And what does that involve?
A.    I maintain records of all the 9-1-1 calls that come in and coordinate our systems and operators.
Q.    That’s a big job—are you the only one who does that?
A.    Sort of. I do have assistants who share some of the work, but I’m the one responsible for it all.
Q.    How long have you been in that position?
A.    Five years now.
Q.    What did you do before that?
A.    I started as a 9-1-1 operator. I did that for three years, and then I became a supervisor. That was my job for two more years, and while I was there, I started to help do some of the stuff I’m in charge of now. That’s how I transitioned into my current role.
Q.    OK, thanks. Now, take a look at these—State’s Exhibits One and Two. Do you recognize them?
A.    I do. Exhibit One is a recording of the 9-1-1 call made on January 1, 2012, from 111 Main Street; Exhibit Two is the call-taker’s notes, which is called a CAD (which is short for computer-aided dispatch).
Q.    How do you know these are the same records that were made that day?
A.    Well, it’s all done by computer, and this is all properly documented. It’s got the information I just gave you on it along with the case number, the time, and the name of the call-taker.
Q.    How does that work—what’s the standard practice when someone calls 9-1-1?
A.    The whole call is automatically recorded, and then the call-taker makes notes as well. The notes are sent out to police officers and other responders as part of the dispatch. That way they know what they’re responding to.
Q.    All right. Are these records kept regularly by the El Paso Police Department?
A.    Yes.
Q.    Are they made at the time of the call?
A.    Correct, as the call is going on.
Q.    And because of that, everything on the recording and in the CAD is based on the personal knowledge of the call-taker and the caller?
A.    Right.
Q.    Is the call-taker an employee of the El Paso Police Department?
A.    Yes, they are.
    That might seem like a lot more than what we did for the photograph, but in principle, it’s the same. The custodian gave her qualifications, connected the evidence to the case, told us how she knew what it was and why it was authentic, and covered the business records stuff. There’s nothing special about these questions—anything that gets the same information out will do.

Generic physical evidence—chain of custody   
A chain of custody is something you need to establish when dealing with generic evidence. When you have a unique thing like a gun, you can point to the serial number on the item and say, “Yep, it’s the same number as the one found at the scene, so we know this is the right gun.”10 When you have something like a baggie of cocaine (which looks much like any other bag of coke), you have some extra work to do. What you need are the beginning and the end of the chain—how something left where it was found and made its way to court, so that we know they’re one and the same.11 The links in between go (you guessed it) to weight, not admissibility:12
Q.    This is what’s been marked State’s Exhibit One. Have you seen it before?
A.    Yes.
Q.    What is it?
A.    It’s an evidence bag containing a knife collected at the victim’s house that night.
Q.    Can you explain how you collected the knife?
A.    When she pointed it out to me, I placed it in this bag, which has a tag on it. The tag has the case number, a description of the piece of evidence, and other identifying information.
Q.    Who filled that information in?
A.    I did. These are my initials on the tag to show that.
Q.    How do you know it’s the same bag and same knife?
A.    It has all the info linking it to this case, it looks exactly how I remember it, and the bag is sealed.
    You may need expert testimony to support things such as lab reports, breath tests, or fingerprint comparisons. Just using the word “expert” makes it seem pretty intimidating, but in reality, experts are easier than lay witnesses because they have a lot more latitude in giving opinions and talking about things they don’t personally know the facts of.13 All they require is a little legwork.
    First you need to qualify the expert by showing she has sufficient background in her field and that her background goes to the opinion she’s going to give.14 After that, tackle the expert’s reliability.

Fingerprint comparison   
Courts have made a distinction between “hard science” and “soft science.” Hard sciences are things such as chemistry or physics. To use evidence based on hard science, all you have to do is show three things: 1) that the underlying theory is valid; 2) that the technique applying the theory is valid; and 3) that the technique was properly applied.15 Soft sciences include psychology or the dynamics of domestic violence. Standards are similar: Courts look to whether 1) the field of expertise is legitimate; 2) the expert’s testimony is within the scope of that field; and 3) the testimony properly relies on the principles of the field.16
    You can meet these criteria by showing how widely accepted the theory is, how qualified the expert is, the literature on the theory or technique, the known rate of error involved, whether there are other experts to test the results, how clearly the science can be explained to the court, or the experience of the person who applied the technique.17 That may take a lot more questions than a photo, but it’s just an expansion of our basic “here’s what I know and why” theory. Let’s take fingerprints:18
Q.    What’s your area of expertise?
A.    Fingerprint comparison.
Q.    How’d you learn to compare fingerprints?
A.    Well, I was first exposed to it on the job as a police officer. Eventually, I was sent to an academy course on lifting and examining fingerprints, which I completed successfully. After that it was on-the-job training, although I did get sent to an advanced FBI course at Quantico where I learned more about using things like IAFIS, which is the national fingerprint database for criminal cases.
Q.    How long have you been doing fingerprint comparisons since the academy?
A.    Four years.
Q.    And how many comparisons have you made?
A.    I can’t say exactly; over a hundred, for sure.
Q.    OK. Let’s start with the basics: what’s a fingerprint?
A.    It’s an impression formed by the ridges of the finger due to sweat, oil, and so forth—well, or ink, if it’s a fingerprint card.
Q.    Are any two fingerprints alike?
A.    No. There’s never been a case where fingerprints from different people have been found to be identical.
Q.    How do you make a comparison?
A.    The ridges in fingerprints are variations of loops, arches, and whorls. Besides a basic visual comparison, we use a formula tied to the ridges on each finger.
Q.    Is that the standard way fingerprint comparison is done?
A.    Yes, it’s a practice accepted pretty much worldwide.
Q.    Let me hand you State’s Exhibit One. That’s a judgment that was previously admitted. Have you had a chance to analyze the fingerprint on it?
A.    Yes.
Q.    And here’s what I’ve marked State’s Exhibit Two. What is it?
A.    This is an inking of the defendant’s fingerprints that I took a little while ago.
Q.    [Move to admit the inking as State’s Exhibit Two.] Have you compared the two exhibits?
A.    Yes, I have.
Q.    How?
A.    Using the same technique I described earlier. I do it the same way each and every time.
Q.    What did you conclude after comparing them?
A.    They’re a match.
Q.    So is the defendant the person who was convicted in the judgment that’s State’s Exhibit One?
A.    That’s correct. They’re the same person, so he was convicted of this prior offense.
    There are certain situations where you need to do a little more work because of statutory requirements; for instance, when talking about a DWI blood draw, you need to establish that the person who drew the blood was a doctor, a qualified technician, a chemist, a registered nurse, or a licensed vocation nurse, and not simply an emergency medical technician.19 But that just comes from learning the law applicable to your case. Generally speaking, if you introduce the witness, get her to talk about what something is and how she knows, and use a business record, chain of custody, or expert predicate if needed, you can lay the foundation for any evidence.

The magic
OK, remember how I said there’s nothing magical about admitting evidence? I lied. There are actually some tricks and special magic words that will get your evidence in easily. The first trick is something you do before trial: filing evidence with the clerk of the court. Lots of things can be admitted this way. Filing business records with an affidavit at least 14 days before trial makes them self-authenticating.20 You can do the same sort of thing with a certificate of analysis (such as the kind in DWI blood draws or drug cases with lab reports). You have to file it 20 days before trial, and if the defense doesn’t object by 10 days to trial, it comes into evidence.21 The same procedure can also be used to establish chain of custody by filing an affidavit.22 A defense attorney may hem and haw about the Confrontation Clause at trial, but this notice-and-demand procedure was specifically approved by the Supreme Court in the leading case on this issue.23 You can save yourself a lot of headaches by doing your homework before trial and filing everything.
    Next, there’s a wide array of stuff that’s self-authenticating: signed or sealed government records, certified public records, published works, periodicals, trade inscriptions, documents that come with a certificate of acknowledgement, and commercial paper.24 The most common of these are prior judgments used for enhancement or impeachment. You may hear some grumbling about confrontation again, but luckily for you, judgments aren’t testimonial,25 so there shouldn’t be any Sixth Amendment concerns.
    The last trick in the bag is a demonstration. Demonstrative evidence doesn’t have a predicate beyond showing that the conditions of the demonstration are similar to what it’s duplicating.26 This approach is great for reenacting how injuries were caused or showing things such as weapons when you don’t have the original for some reason. “How does this compare to the knife the defendant used to threaten you? Why, they look the same? Goody! Jury, have a look at this scary knife!”
    Oh, and I promised you magic words. Abracadabra, hocus-pocus: “We stipulate.” Before you’ve got a defense attorney objecting, before you even start trial, why not just ask the defense whether they have a problem with you introducing certain evidence? You’d be amazed at what you can get in simply by discussing it beforehand.
    What this article has covered isn’t the last word on evidence, of course. Among other things, I left out statements and the rules about hearsay and confrontation that go with them, which we’ll cover in another “back to basics” article down the line. But this should be enough to put you back on the rails, armed with enough guiding principles to make admitting evidence a piece of cake, and free to deal with the million and one other crazy things that can crop up during trial. Good luck, and go get ’em!


1 Tex. R. Evid. 901(a).
2 Id. (b).
3 See id. 103(a)(1) (no error preserved regarding evidence unless objection is specific); Long v. State, 800 S.W.2d 545, 548 (Tex. Crim. App. 1990) (objection must be specific enough to give State notice of legal grounds and opportunity to cure objection); City of Mesquite v. Moore, 800 S.W.2d 617, 619 (Tex. App.—Dallas 1990, no writ) (“A valid objection to an offer of evidence is one that names the particular rule of evidence that will be violated by admission of the evidence”).
4 Tex. R. Evid. 901(b)(2).
5 See Black v. State, No. 02-10-00283-CR, 2012 WL 117970, at *7 (Tex. App.—Fort Worth Jan. 12, 2012, no pet.) (no showing defendant “wrote or ratified” text messages precluded their introduction as admission of party opponent); Stafford v. State, 248 S.W.3d 400, 408 (Tex. App.—Beaumont 2008, pet. ref’d) (covering authentication of handwriting through lay witness); Shea v. State, 167 S.W.3d 98, 105 (Tex. App.—Waco 2005, pet. ref’d) (covering authentication of emails). Note that digitally preserved documents are just as admissible as those kept on paper. Tex. Code Crim. Proc. art. 38.44.
6 See generally Long v. State, 823 S.W.2d 259, 270 (Tex. Crim. App. 1991) (describing foundation for admitting photographs); Kelley v. State, 22 S.W.3d 642, 644 (Tex. App.—Waco 2008, pet. ref’d) (same).
7 Personal knowledge is the basic requirement for all testimony, and it’s enough to get evidence in. Tex. R. Evid. 602 & 901(b)(1).
8 Tex. R. Evid. 803(6).
9 Tex. R. Evid. 902(10); Montoya v. State, 43 S.W.3d 568, 571–72 (Tex. App.—Waco 2001, no pet.); Brooks v. State, 833 S.W.2d 302, 304 (Tex. App.—Fort Worth 1992, writ ref’d).
10 Tex. R. Evid. 901(b)(4).
11 E.g., Stoker v. State, 788 S.W.2d 1, 10 (Tex. Crim. App. 1989); Maranda v. State, 253 S.W.3d 762, 770 (Tex. App.—Amarillo 2007, pet. stricken); Caddell v. State, 123 S.W.3d 722, 727 (Tex. App.—Houston [14th Dist.] 2003, pet. ref’d).
12 See Lagrone v. State, 942 S.W.2d 602, 617 (Tex. Crim. App. 1997) (without evidence of tampering, chain of custody goes to weight, not admissibility); Stoker, 788 S.W.2d at 10 (same).
13 See generally Tex. R. Evid. 702–705 (laying out standards for expert testimony).
14 Vela v. State, 209 S.W.3d 128, 131–32 (Tex. Crim. App. 2006).
15 Kelly v. State, 824 S.W.2d 568, 573 (Tex. Crim. App. 1992).
16 Nenno v. State, 970 S.W.2d 549, 561 (Tex. Crim. App. 1998).
17 Kelly, 824 S.W.2d at 573.
18 See Gibbs v. State, 544 S.W.2d 403, 404 (Tex. Crim. App. 1977) (describing how fingerprint comparisons made and admitted); Acevedo v. State, 255 S.W.3d 162, 171–72 (Tex. App.—San Antonio 2008, pet. ref’d) (providing proper standards for qualifying fingerprint expert); Cooks v. State, No. 05-02-01809-CR, 2004 WL 42612, at *1 (Tex. App.—Dallas Jan. 9, 2004, no pet.) (describing how fingerprint comparisons made and admitted). Fingerprints are something you’ll get a lot of practice with, since they’re used for linking a judgment or booking sheet’s prints to a fresh sample from a defendant. E.g., Beck v. State, 719 S.W.2d 205, 210 (Tex. Crim. App. 1986).
19 Tex. Transp. Code. §724.017(a).
20 Tex. R. Evid. 902(10). The form you need for the affidavit is in subsection (b).
21 Tex. Code Crim. Proc. art. 38.41. The certificate you need is found in §5.
22 Tex. Code Crim. Proc. art. 38.42. Again, the certificate you need is in §5.
23 Melendez-Diaz v. Massachusetts, 557 U.S. 305, 326–27 (2009).
24 Tex. R. Evid. 902.
25 Smith v. State, 297 S.W.3d 260, 276 (Tex. Crim. App. 2009).
26 Cantu v. State, 738 S.W.2d 249, 255 (Tex. Crim. App. 1987), cert. denied, 484 U.S. 872 (1987). If you can’t get an original, something similar is admissible as long as it doesn’t have “inflammatory attributes” that the original didn’t. Simmons v. State, 622 S.W.2d 111, 113–14 (Tex. Crim. App. 1981).