A resident of Mayflower Residence Hall was assaulted  Tuesday afternoon around 2 p.m. as he was leaving the northeast  entrance of the building, according to a press release.
The suspect wore a ski mask and reportedly punched  the victim in the back of the head and attempted to steal his wallet. A  Good Samaritan stepped in and was able to aid the victim in retrieving  the wallet, the release said.
According to UI police, the suspect is described  as a 25- to 30-year old black male, 6 foot, 200 pounds; he was last seen  wearing all black clothing and black Nike-style basketball shoes. The  alleged victim also said there appeared to be a cut design in his hair  on the right side of his head. 
UI police are also seeking the Good Samaritan, who  is described as an older white male, possibly 40 to 50 years of age,  who might go by the name Mark or Clark. He is described as 5-10, 170  pounds, with a thin silver mustache and light brown hair.