She got into a car, and police seem to be only searching the nearby park. A car means that she could be anywhere, but it is important to be thorough searching "walking distance" areas.
Other than the screams, why do police believe that she is still in the vicinity of the bench? Do they think that she was abducted, taken to the nearby park, assaulted and murdered? Couldn't she have been assaulted at the park and taken back to his car, and then driven farther away?
If he's a first time serious offender, wouldn't he want to distance the body from his home - even if he met the victim near his home? If so, her body is probably within 15 - 20 miles of his home. That seems to be the standard distance for first timers.
I read something about 3AM. If she was abducted at 12:08, were there 3 hours in the park, or 20 minutes in the park and then driving to some other place and returning home around 3AM? Or is the 3AM the time when her roommates arrived at home and reported her missing?
When was she reported missing ... 10AM or 3AM?