Is the movie script of arsenic and old lace in public domain?

The play "Arsenic and Old Lace" by Joseph Kesselring was published in 1941 and the movie script based on the play was released in 1944, so the copyright for both the play and the movie script would still be in effect, lasting for the life of the author plus an additional 70 years. Joseph Kesselring died in 1967, and 70 years after this date would be 2037.

To determine if a work is in the public domain in the US, you need to consider the date of creation, the date of the author's death, and whether the work was published before 1978. Based on the information you provided, it seems that the play and movie script for "Arsenic and Old Lace" are still under copyright protection in the US and not yet in the public domain.