CHICAGO (AP) – Prosecutors are building a case based partly on a bloody handprint and the responses of a cadaver-sniffing dog that a former University of Illinois student killed a Chinese scholar in his apartment.

Prosecutors revealed evidence in a recent series of filings that they say will help prove Brendt Christensen kidnapped and killed Yingying Zhang in Urbana in 2017.

His trial begins April 1. Prosecutors are seeking the death penalty .

In a filing Wednesday, prosecutors disclosed the handprint was found in Christensen’s apartment, though it’s unclear if they believe it’s Christensen’s or Zhang’s. Prosecutors also say a cadaver-sniffing dog detected traces of a dead body around the bathroom sink.

Christensen’s lawyers want the judge to bar much of that evidence. They argue the dog is unreliable because it wasn’t properly trained.