Parris pleads with Danforth to pardon or postpone the executions in the final act of the play. His evidence offers a combination of selfish hope and selfish fear.
First, Parris allows Hale into the jail to speak with the condemned and convince them to confess. A confession would lend credence to the executions, which Parris worries have fallen out of favor in the town.
Parris uses this idea as support for postponing the executions. If Hale can be given more time to sway the condemned to confess and succeed, the executions will be validated.
When Danforth resists, Parris confesses that a dagger clattered to his doorstep when he left his house to come to the jail. He feels that he and the court are threatened and may be subjected to violence if the executions are carried out.