Matthews, 21, was charged in state district court with eight felonies, the most serious of which are three counts of gross sexual imposition, each carrying a maximum penalty of life imprisonment.
Matthews was accused of breaking into two college women's apartment in the north end of Grand Forks last year and then robbing and raping them at gunpoint.
The prosecution rested its case yesterday, and the defense decided not to call any witnesses. Matthews chose not to testify in his defense.
In closing statements, Assistant State's Attorney Jason McCarthy argued that all of the evidence and testimony fits together in a solid case against Matthews.
He reminded jurors of the evidence found in Matthews' home and vehicle: the victims' cell phones and several articles of clothing and a gun matching the victims' descriptions of their attacker's clothing and weapon.
McCarthy pointed to DNA analysis that found the two victims "could not be excluded as contributors" to DNA found on the purple polo shirt confiscated from Matthews' home, meaning their DNA might have been present on the shirt.
According to witness testimony, there is a relatively small pool of people who could be identified as possible contributors to the DNA found on the purple polo, which the victims described their attacker as wearing.
Matthews also bears tattoos resembling the victims' descriptions of their attacker's tattoos.
McCarthy said in closing remarks that Matthews was using the "mystery man defense."
"That mystery man is the defendant," said McCarthy. "He's the man that put (the victims) through the worst nightmare of their lives."
Defense Attorney David Ogren urged the jury in his closing statements to ask questions. He pointed out that some of the items stolen from the victims' apartment were never recovered, including a tan wallet, a credit card and a bottle of peach schnapps.
He also asked whether other people could have gained access to Matthews' vehicle, which police testified was unlocked.
The 12-member jury is expected to have a verdict by today.