University of Wisconsin police arrested a suspect Thursday in connection to a late-night robbery in Witte Hall earlier this week. The suspect turned himself in to Dane County Jail officials yesterday morning on a variety of unrelated outstanding warrants, according to UWPD Sgt. Michael Newton. An anonymous Crime Stoppers tip helped lead UW police detectives to question the suspect about the robbery at Witte, Newton said, and after one of the robbery victims positively identified the suspect in a photo line-up, police made the arrest. "Based on the fact of the positive I.D. in the photo line-up, we definitely believe this is the suspect in this case," Newton said. Newton added police will file formal charges after completing interviews with the suspect. "At this point, we're still in the middle of the investigation," Newton said. "After the interviews, we'll know more about the charges filed." According to university police, at approximately 11:45 p.m. Tuesday the suspect entered the dorm room of two female Witte Hall residents, grabbed one student by the throat and demanded money and valuables. The suspect then made off with an undisclosed amount of money. Newton said police are still investigating how the suspect gained entrance into Witte Hall, a public dormitory equipped with 24-hour locks on all exterior doors and security cameras monitoring the first floor entrances. With the suspect in custody, Interim Dean of Students Lori Berquam applauded the efforts of the UWPD. "I'm really happy with our police and the efforts they put out to get this particular perpetrator," Berquam said. "I'm sure the victims feel relieved, as do all the residents [of Witte Hall]." Berquam added the Offices of the Dean of Students has contacted the two victims since the incident and offered all available crisis services to them and their families. Newton credited the tip from Crime Stoppers in helping police make Thursday's arrest. "For us, Crime Stoppers is invaluable," Newton said. "Information is key for us. When people give us information, we can follow up on the leads." Newton added he did not want to speculate as to why the suspect — who remains in custody — turned himself in to UWPD. "We don't know what motivation led to him turning himself in," Newton said. Tuesday night's robbery is the second attack on or near the UW campus this semester. On Jan. 28, Madison police responded to a robbery of an 18-year-old man on the 100 block of Langdon Street. The man was reportedly visiting his sister, a UW student, and was considering attending the university himself next fall.