Christians desired to see whether Jesus's body was missing from its tomb.
Wolfhart Pannenberg (Systmeatic theology professor at Harvard [and others]): “Christians must have attached great interest to this question.” [Jesus - God and Man (Westminster, 1968), 101.]
The physical trek to the grave was prohibitively difficult/undesirable. (That is to say, it was too inconvenient to visit Jesus's tomb to see if it was empty.)
But wait, the grave was right there in Jerusalem.
J. N. D. Anderson (Dean of Law at London): “It is a matter of history that the apostles from the very beginning made many converts in Jerusalem, hostile as it was, by proclaiming the glad news that Christ had risen from the grave-and they did it within a short walk from the sepulchre. Any one of their hearers could have visited the tomb and come back again between lunch and whatever may have been the equivalent of afternoon tea.” [Christianity: The Witness of History (Tyndale, 1969), 95-96.]
The church could not know if the corpse they were looking at was Jesus's because of severe decomposition.