Gregg Michael Langley challenges his convictions for traveling in interstate commerce for the purpose of engaging in illicit sexual conduct with a minor, and using a means of interstate commerce to persuade, induce, entice, or coerce a minor to engage in sexual activity for which a person could be charged with a crime. We affirm.
I
In February 2006, then fourteen-year-old J.C., who was living in Missouri, was approached online by then thirty-year-old Langley, who was living in Arkansas. Via instant messenger, J.C. chatted online with Langley using two different Yahoo! user profiles. Langley also asked J.C. for her phone number, and they spoke on the phone.
Initially, J.C.’s online profiles listed her age as eighteen and twenty-one years old. J.C. selected these ages because Yahoo! requires an individual to be eighteen years old to create a profile. After J.C. and Langley began communicating, J.C. changed one of her Yahoo! profiles to reflect her true age, fifteen years old. Langley noticed this change, and said, “I thought you were 18.” J.C. responded, “I told you that, but I’m really 15.” Langley responded, “Just don’t tell nobody. I don’t want to get in trouble.”
When the Internet chats and phone calls first began, they were casual conversations about work and school, but they turned sexual. Langley talked about J.C. coming to his house in Arkansas, and the sexual acts he wanted to do with and to J.C., including J.C. performing oral sex on him.
*728One time when Langley called J.C.’s grandmother’s house to talk to J.C., J.C.’s stepmother, Ashley Meyers, answered the phone. Langley thought he was talking to J.C., and Meyers pretended to be her. Meyers believed Langley to be an older man due to his voice, and was disturbed by the conversation, which included Langley saying he missed J.C. and asking for more photographs of her. The next morning, Meyers confronted J.C., who admitted she was communicating with a grown man. Meyers called the local police, who advised her to contact Detective Jim Murray with the Diamond Missouri Police Department because he specialized in investigating online crimes.
On April 21, 2006, Detective Murray, posing as J.C., began chatting online with Langley. Langley requested they meet, and they arranged to meet that night at Blimpie’s in Jane, Missouri. During the Internet chat, Langley said J.C. could spend the night at his home, and would “have more fun than u could imagi[n]e.”
When Langley arrived at Blimpie’s to rendevous with J.C., he saw a police officer and drove away because he was “scared.” After the failed meeting, Langley and Detective Murray chatted online again. Langley again discussed the sexual activities he wanted to perform with J.C. They decided to meet later in the week.
During an online chat on April 23, 2006, Langley talked about how much he wanted J.C. to perform oral sex on him and to have sexual intercourse with her. They arranged to meet at the EZ Mart in Ben-tonville, Arkansas. Detective Murray suggested they celebrate J.C.’s fifteenth birthday when they met. Langley stated he thought she was fifteen now, and asked how old she was turning. Detective Murray confirmed J.C. was turning sixteen, and thus was currently fifteen.
On April 28, 2006, Bentonville police officers waited for Langley at the EZ Mart in Bentonville, Arkansas. Langley was told J.C. would be in a white truck, and a decoy truck was in the parking lot. He pulled into the parking lot, stopped next to the decoy truck, and then drove away. Ben-tonville Police Department officers stopped Langley and arrested him.
That same day, Bentonville police officers executed a search warrant at Langley’s apartment and seized his computer. On Langley’s computer, the officers found eight photographs of a nude to partially-nude girl who appeared to be less than eighteen years old. Five of the photographs depicted this apparent minor engaging in sexually explicit conduct. The girl in these photographs was never identified.
Langley was indicted for traveling in interstate commerce for the purpose of engaging in illicit sexual conduct with a minor in violation of 18 U.S.C. § 2423(b), and using a means of interstate commerce to persuade, induce, entice, or coerce a minor to engage in sexual activity for which a person could be charged with a crime in violation of 18 U.S.C. § 2422(b).
Prior to trial, the government filed a Notice of Intent to Introduce 404(b) Evidence, seeking permission to admit the eight photographs found on Langley’s computer. Langley filed a motion the following day to exclude such evidence, which the district court1 denied.
A four-day jury trial commenced on August 27, 2007. During trial, the photographs were admitted with a limiting in*729struction that they were only admissible to show Langley’s motive, opportunity, intent, preparation, plan, knowledge, or absence of mistake or accident. The jury found Langley guilty on both counts.
Langley was sentenced to 78 months imprisonment on each count, to run concurrently, a five-year term of supervised release, a $10,000 fine, and a $200 special assessment. This appeal followed.
II
On appeal, Langley seeks to overturn the guilty verdict because: (a) the district court improperly admitted the eight photographs of an apparent minor; and (b) there was insufficient evidence to find him guilty on either count.
A
We do not reach the issue whether the district court erred in admitting the photographs of an apparent minor because, regardless of whether an error actually occurred, any error was harmless. We review the district court’s decision to admit evidence for abuse of discretion. United States v. Lucas, 521 F.3d 861, 865 (8th Cir.2008). “We will reverse a conviction only when an improper evidentiary ruling has affected substantial rights or had more than a slight effect on the verdict.” United States v. Cannon, 475 F.3d 1013, 1023 (8th Cir.2007) (internal quotation marks omitted). “An evidentiary error is harmless when, after reviewing the entire record, we determine that the substantial rights of the defendant were unaffected, and that the error did not influence or had only a slight influence on the verdict.” United States v. McPike, 512 F.3d 1052, 1055 (8th Cir.2008) (internal quotation marks omitted).
We do not overturn Langley’s conviction because any asserted error by the district court was harmless. The case against Langley was strong. Viewing the evidence in favor of the verdict, it demonstrates Langley believed J.C. was below the age of consent (discussed infra), used a means of interstate commerce to persuade and induce her to engage in illegal sexual acts, and traveled across state lines for the purpose of engaging in illegal sexual acts with her. Therefore, irrespective of whether the district court erred in admitting the photographs, such error was harmless.
B
There was sufficient evidence to convict Langley on both counts in the indictment. Langley argues there was insufficient evidence because it was “unclear” whether he knew J.C. was under the age of sixteen. J.C.’s testimony, Langley’s behavior evidencing a consciousness of guilt, and the transcripts of the Internet chats between J.C. and Langley, however, are sufficient evidence for a reasonable jury to conclude Langley believed J.C. to be under the age of sixteen.
We review “the sufficiency of the evidence de novo, viewing evidence in the light most favorable to the government, resolving conflicts in the government’s favor, and accepting all reasonable inferences that support the verdict.” United States v. Piwowar, 492 F.3d 953, 955 (8th Cir.2007). We will “reverse only if no reasonable jury could have found the defendant guilty beyond a reasonable doubt.” United States v. Birdine, 515 F.3d 842, 844 (8th Cir.2008).
Both offenses with which Langley was charged require the government to demonstrate he believed J.C. to be under the age of sixteen. The § 2422(b) offense is “limited to conduct that persuades or attempts to persuade a minor to engage in sexual activity ‘for which any person can be *730charged with a criminal offense.’ ” United States v. Patten, 397 F.3d 1100, 1103 (8th Cir.2005) (quoting 18 U.S.C. § 2422(b)). We look to state law to provide the underlying criminal offense. Id. In Arkansas, it is a criminal offense for a defendant, age twenty years or older, to engage in sexual intercourse or “deviate sexual activity”2 with another person who is less than sixteen years of age. Ark.Code Ann. § 5-14-127(a)(1). Similarly, the § 2423(b) offense is limited to traveling in interstate commerce “for the purpose of engaging in any sexual act ... with a person under 18 years of age that would be in violation of Chapter 109A.” 18 U.S.C. §§ 2423(b) and (f). Chapter 109A proscribes engaging in a sexual act3 with a person who attained the age of twelve but not sixteen. Id. § 2243(a); United States v. Blazek, 431 F.3d 1104, 1108 (8th Cir.2005).
Langley contends there was insufficient evidence to conclude he believed J.C. was under the age of sixteen because J.C.’s online profiles initially stated she was eighteen and twenty-one years old. This is incorrect. J.C. testified she told Langley she was not eighteen years old, as stated in her initial online profile, rather she was fifteen years old. His only response was to instruct her not to tell anyone they were communicating or he could get into trouble.
In addition, Langley decided to abort their planned meeting at Blimpie’s because he was “scared” of the police officers on the scene. It is reasonable to conclude he was scared of the police because he knew he was about to engage in illegal activity, 1.e., he knew J.C. was under the age of sixteen.
The jury also viewed and examined the Internet chat log from April 23, 2006. Detective Murray, posing as J.C., typed the wrong age for J.C. Langley noticed, evidencing his belief she was fifteen years old:
J.C.: maybe we can celebrate my [birthday]
J.C.: i will be 15 next month
Langley: sure
Langley: wait
Langley: u said ur 15 now
Langley: and ur turning 15
Langley: 16
J.C.: yes
Langley: not 15
J.C.: we can celebrate it
Langley: how old will u b
Langley: ?
Langley: 15 or 16?
J.C.: 16
Based upon J.C.’s testimony, evidence of Langley’s consciousness of guilt, and the above online colloquy, a reasonable jury could find Langley believed J.C. was under sixteen years of age. Although Langley testified he was confused as to J.C.’s age, we will not second-guess credibility determinations made by the jury during trial. Birdine, 515 F.3d at 844. Accordingly, Langley has not demonstrated there was insufficient evidence to support his convictions.
Ill
We affirm Langley’s convictions.
. The Honorable Jimm L. Hendren, United States District Judge for the Western District of Arkansas.
. "Deviate sexual activity'' is defined to include oral sex. Ark.Code Ann. § 5-14-101(1)(A).
. "Sexual act” is defined to include oral sex. 18 U.S.C. § 2246(2)(B).