Heriberto Viramontes is charged with attempted murder, aggravated battery and armed robbery after authorities say he beat Stacy Jurich and grad student Natasha McShane. McShane, who still cannot talk or walk, is from Northern Ireland. Her family came to Chicago for the trial.
Jurich was the first witness called by prosecutors in the trial of Viramontes.
Jurich testified: "I heard my head being hit and I felt excruciating pain. And I lost my equilibrium."
Jurich told jurors "I saw Natasha being hit on the head." An assistant state's attorney asked "Did you see what she was being struck with? Jurich responded "A bat."
Then Jurich tearfully described seeing her friend afterward. "She was not moving on the ground. The blood started coming out of her head. I took my jacket and supported her head as much as I could. And I ran for help."
McShanes mother testified that the active, energetic young woman working in her masters at UIC at the time of the attack now requires constant care.
"Now she doesn't speak or walk on her own. She suffered two seizures. One so severe she had to have hip surgery because she was shaking so badly and ultimately her hip had to be replaced," Sheila McShane told the court.
Jurors also saw videos of Natasha McShane as she struggled in physical therapy after the attack and her ongoing struggle with everyday things, like holding a cup and taking steps - only with assistance.
Both women were beaten and left on a Chicago street. Jurich needed staples in her head. Authorities said the 37-year-old Viramontes stole the women's purses.
Viramontes' attorney, Assistant Public Defender Chandra Smith, said she'll call a witness who says he saw a different man with a baseball bat in the area shortly before the attack.
McShane and Jurich, then 23 and 24 years old, were walking home when they were brutally beaten with a baseball bat.
"It seems like a nightmare you want to wake up from, but it is happening. We are going to have to deal with it. All we have to do is move on and pray and hope Natasha will be better, which she will be," Conor McShane, Natasha's brother, told the British Broadcasting Corporation.
Marcy Cruz was also charged in the case. She pleaded guilty to attempted murder. In a plea deal for a lesser sentence, she will testify against Viramontes. She is expected to say she was in a van with Viramontes in the early morning hours of April 23, 2010, when he left with a bat and returned to the vehicle later with two purses.
"The Irish community has come together in Chicago and the suburbs to run benefits and welcome the family and bring them in our homes and try to show them the good side of Chicago," said John Gorski, Irish American Heritage Center.
"This is a young woman whose life has been altered forever. Hopefully they'll get this guy off the street so that he can't do this to anyone else. That's something, I don't think it will make up for what he's done, but that's something," said Bobby McGuire, McShane's former employer.
The Associated Press contributed to this report.