Neal Grubbs was jailed on preliminary charges of possessing a destructive device after his arrest Tuesday. The Indianapolis Star reports investigators went to his home on the city's west side after a 911 caller reported that Grubbs planned to set off the tennis ball bombs in two suburban movie theaters.
Police spokeswoman Officer Nicole Headlee say investigators took the report seriously to stop any potential attack.
Grubbs' mother told WTHR-TV and WRTV that she believes the tennis ball was left in their home by a former friend of her son who then called police to seek revenge after a fight.
