Looks like different pens, one to Daschle looks like wider felt-tip marker; second looks like marker but narrower nib, also may be running short on ink. Ink smeared by water on the one indicating non-indelible ink.
Now that I can read the return-address zip clearly, it is Monmouth Junction, NJ. That would be Middlesex County. MIT place locator shows three Franklin Parks, one in Burlington County, one in Middlesex County, and one in Somerset. Middlesex County might be a place to start.
The person who filled the envelopes could have started the process in a different location and passed them off to someone in NJ to mail so it doesn't mean they necessarily originated in NJ, although the mailer seems fixated on NJ with the cities and zip code even though the school is phoney. Middlesex County is between NY and Trenton. May have been taken to Trenton to mail or may have been collected in a mail drop further north and postmarked in Trenton. Probably both mailed sometime during the day; can't read the time stamps on the postmark.
Sure hope they can unravel this one. Can't think of anything else at the moment.