Max Demby, a University of Colorado senior, was walking home from the Engineering Center early April 4. When he turned the corner, he said, he saw a woman being attacked.

“It was just a routine walk home, and I just walked right into it,” Demby said. “I knew something was wrong, and I knew I had to do something. There was never a doubt in my mind.”

The CU Police Department said Demby intervened to stop a sexual assault that morning when a man — identified by police as Andrew Souser, 27 — attacked a female student.

Demby said he rounded the corner and saw a man pinning the student against a wall.

“He was definitely overpowering her,” said Demby, who was able to separate the two. The assailant took off, and Demby walked the woman home.

Police had been trying to identify Demby — an accounting major and a Ralphie handler at CU — since he reportedly broke up the attack. Demby said he saw the media reports seeking to identify him several days later and called police to give a statement.

“It was then that I realized how serious it was and how glad I was that I was there to help,” Demby said. “I don’t know if I’m a hero; I’m just glad I could be in the right place at the right time.”

Demby has not spoken to the victim since the attack, but he said the gravity of what happened has sunk in.

“I never thought I would have been involved in something like this,” he said. “It was just a regular walk home.”

Although Demby hesitated to call himself a hero, CU police did not.

“Max is a hero,” said CU police Deputy Chief Ken Koch. “I know he would cringe at that like many of us would, but, bottom line, he interceded in an event that would have ended much worse than it did. Because of that choice, a fellow student, a fellow member of our university, has a much less traumatic event to deal with.”

According to police, the female student called police at 2 a.m. April 4 and said she had been sexually assaulted near the Engineering Center after being followed from University Hill.

Based on the victim’s description, officers launched a search for the suspect.

A second woman contacted police shortly before 3 a.m. and said a man had approached her near the University Memorial Center, making sexually suggestive comments and trying to touch her. She gave a similar description of the suspect in the first attack.

Officers found Souser in the area of the UMC. Police say he gave officers a false name before being arrested.

Souser was charged Thursday with sexual assault and attempting to influence a public servant, both felonies.

Souser also is charged with two counts of misdemeanor harassment and one count of attempted unlawful sexual contact.

But police and prosecutors are still concerned that Souser may be a suspect in additional cases over the past four months since he has been in Boulder, and they are asking anyone who may have been a victim or a witness to contact police.

“There is a very strong likelihood this individual has done something like this before,” Koch said. “We have unsolved sexual assaults and similar activities not only on campus but in the Boulder community as well. Based on the timeline we know this individual to be in the area, those are consistent with the timeline of these assaults.”

Souser remains in custody without bond as he undergoes a competency hearing. He is scheduled for a review in June.

Because police are still looking into the possibility he was involved in other cases, police are not releasing Souser’s booking photo.

Mitch Byars: 303-473-1329, byarsm@dailycamera.com or twitter.com/mitchellbyars