A criminal case requires a much higher burden of evidence

Only a single witness statement is needed for a criminal conviction.

See the following:

From https://www.law.cornell.edu/nyctap/I07_0020.htm on rape accusations:

"'[T]he testimony of a single witness [can be enough] to support a conviction' (People v Schulz, 4 NY3d 521, 530 [2005] quoting People v Arroyo, 54 NY2d 567, 578 [1982]). Although corroboration is not necessary in support of a rape prosecution, the underage victim's testimony was bolstered by her prompt outcry the morning after the first rape occurred..."

From https://www.justice.gov/atr/case-document/united-states-proposed-jury-instructions on jury instructions:

"Similarly, the government is not required to prove the essential elements of the offense by any particular number of witnesses, or by every witness. The testimony of a single witness can be sufficient to convince you beyond a reasonable doubt of the existence of an essential element of the offense charged if you believe that the witness was truthful."

All it takes is for a single claim and for the jury to think that they are truthful.

Ask a lawyer: https://www.avvo.com/legal-answers/-so-if-there-is-no-physical-evidence-other-than-wi-1717488.html

Q: “So If there is no physical evidence other than withness testimony, can one still be convicted? Would it be hard for the prosecution to get a conviction?”

Benjamin David Goldberg, Criminal Defense Attorney in Marietta, GA, answers:

A: "The answer to your first question is yes. In fact, judges often instruct juries that the testimony of a single witness is sufficient to establish a fact. That means that, for most offenses, a person can be convicted based solely on another person's testimony (unless that other person is an accomplice). The second question is impossible to answer without knowing all the facts and circumstances of the particular case."

https://www.slgattorneysflorida.com/the-state-only-has-one-witness-isn-t-that-hearsay.html

"We often get questions about whether the State can convict you of a crime when they only have one single witness in a "he said/she said" type of case. We usually get the question, "Isn't that hearsay?" Is "he said/she said" testimony hearsay and inadmissible?

No. Eyewitness testimony is not hearsay. Hearsay relates to when a witness testifies about an out of court statement. For example, if Jill testifies, "John told me that Phil punched him," this statement is hearsay because Jill is testifying about John's out of court statement. Now if John testifies that Phil punched him, that is not hearsay, because John is testifying to what happened, not what somebody told him.

Also, hearsay is not always inadmissible. There are many exceptions to the hearsay rule where an out of court statement would be admissible."

https://splinternews.com/people-are-convicted-based-on-one-witness-all-the-time-1829367479

People Are Convicted Based on One Witness All The Time

"I rob you on a dark, deserted street at night. You call the police. You describe me. The police find me. You confirm it was me. You testify against me. I go to jail. This sort of thing is completely normal.

Sure, the police and prosecutors would like to have as much evidence as possible. They would like to have another witness, or my DNA, or to find the items that I stole from you in my possession. But if they don’t have any of those additional things—if they only have your own testimony that I robbed you—I have news for you: they will still arrest me. And, if the jury finds your testimony to be credible, they will find me guilty, and I will go to jail."