The incident occurred about two miles from campus.
The incidents were reported between Nov. 10 and Nov. 18.
The individual involved is in serious but stable condition after a shooting outside a liquor store.
Students who test positive for COVID-19 on or after Dec. 8 will need to isolate at their permanent residence or elsewhere.
There were no weapons involved, according to police.
Police canvassed the area, but did not find anyone who posed a threat.
Two remain hospitalized with non-life-threatening injuries, police say.
The testing, which started in October, will continue into the spring semester.
Trails in the College Park, Hyattsville, Riverdale Park and Bladensburg areas will be closed until further notice.
Preliminarily, police do not believe that this is a random shooting.