Looking for how to find if an user modifying file?

i have tried something as below but it doesn't tell who is user of file( not looking for owner)
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find /home/usr -name "[A-Z][A-Z]" -type d -exec basename {} \; > state_list
#how to exclude entry like SS, TT in file state_list ??
while read x
for y in `find /home/usr/${x} -name "STATS.[A-Z]*" -mtime 0 -print|sed '/TEST/d'|grep -v [a-z]|grep -v [0-9]`

#filename is STATS.${county} where county is ALPHA string

echo file $y has been modified|mailx -s "stats file" ${mail_list}
done < state_list

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