What is a more modern variant of the interjection 'Lo!"

What is a more modern variant of the interjection 'Lo!"

I'm looking for a single word which has the same effect but is less archaic.

It is a very formal context I want to use it in that you may find in a courtroom for example: 'He claims he is innocent of corruption, but lo! He is guilty of taking bribes!"

Historically, “lo!”, isn’t expressive of any particular emotion (alas) or addressed to any particular person (dude), and it's not an all-purpose interjection (Hey). It expressly calls upon hearers to look at, to take account of, to behold what follows.

In contemporary English we say “look!” in pretty much exactly the same way.

He claims he is innocent of corruption, but look! He is guilty of taking bribes!

For that matter, so did Shakespeare. Hamlet, I, i, 40, the Ghost’s first appearance:

Marcellus: Peace, break thee off; look, where it comes again!

And at the second appearance, 86 lines later

Horatio: But soft, behold! lo, where it comes again!

"Hey" seems to be in the modern idiom. So,

"He claims he is innocent of corruption, but hey! He is guilty of taking bribes!"

There are a couple of possibilities, but none as satisfyingly interjective as Lo!

He claims to be innocent of corruption, but, he is guilty of taking bribes.
He claims to be innocent of corruption, yet, he is guilty of taking bribes.
He claims to be innocent of corruption; however, he is guilty of taking bribes.
He claims to be innocent of corruption; nevertheless, he is guilty of taking bribes.
He claims to be innocent of corruption; nonetheless, he is guilty of taking bribes.
He claims to be innocent of corruption; that notwithstanding, he is guilty of taking bribes.

Consider alas (Interjection, “Used to express sorrow, regret, compassion or grief”) and behold.

He claims he is innocent of corruption, but alas! He is guilty of taking bribes!

As noted in earlier comments, behold is a more modern form of lo (Interjection, “(archaic) Look, see, behold”). Whether behold is archaic (as John Lawler suggested) I can't say; wiktionary's “Usage notes” for it say “Rarely used in informal speech.”

Alas also may seem archaic to some, but a few writers, including Jerry Pournelle, still use it frequently. Note, alas (or alack) expresses a note of regret, unlike either of behold and lo, which bring with them overtones of “I told you so”.