Initially suspected to be a murderer, Alex turns out to be Dexter's first (more or less) innocent victim in the Novel continuity.
After four bodies appeared in one day, staged in some form of modern art, Dexter is puzzled why is his Dark Passenger doesn't have any idea about it. As the bodies are some twisted interpretation of tourist attraction, Dexter and Deborah visited The Greater Miami Convention and Visitor's Bureau and find out that they were supposed to be harmed by attacks in the first place as they have a DVD sent to them which depcits what is supposed to be murders as well as people reacting to them in the fashion of tourist commercials.
After picking up a list of recently fired people as their suspects, they visit a few of them and then they have an argument about Dexter being a serial killer. Because of that, when they visit yet another suspect, a Canadian citizen who used to work as a writer for bureau before getting fired and even removed by security from the place, Dexter remains in the car. Meanwhile, after showing her badge, Deborah gets stabbed. Dexter catches a man who is supposed to be an attempted murderer, Alex Doncevic, but his lawyer, Simeon has him freed.
Nearly improvising, Dexter kills Doncevic the same night using the instruments he supposedly used to kill his victims, especially a surgical saw. Dexter is greatl puzzled by Doncevic's last word: "Smile."
It later turns out that Doncevic wasn't the killer and wasn't even an attempted murderer. The four bodies were stolen from the morgue and the knife which was used to stab Deborah had other thumbprints on it, those of Weiss.
Later, Dexter receives an e-mail with a YouTube video of him killing Doncevic. The murder of Doncevic causes his lover, Brandon Weiss to kill Robert Deutch as a message to Dexter.
It should be noted that the characters of Oscar Prado and Jonathan Farrow from the TV Series are very similar to Doncevic. Prado was an attempted murderer killed by Dexter (and his first more or less innocent victim, as well as partially improvised like Doncevic). Farrow was an even more innocent victim, though his personality and art were very disturbing. Both also had their lawyers get them free of charges and both were framed by their associates. It should be noted that although Farrow seem to be partially based on Doncevic, there is only a small gap between the novel and the filming of Season Fouris.
Alex is also similar to Viktor Baskov as his murder by Dexter leads into a killing spree by his lover who snapped.
Doncevic has no confirmed kills. Although he was suspected of killing four people, they turned out to be corpses stolen from morgue. As Masouka says, however, “It's still a felony... Stealing a corpse, desecrating the dead, something like that. Endangering public health? I mean, it's gotta be illegal.”
He might be considered Weiss's accomplice to an attempted murder of Deborah Morgan as he didn't give up Weiss.