Don’t write the -ed and -ing forms of commit with only one ‘t’. The correct spellings are committed and committing:
✗ His wife went mad and commited suicide.
✓ His wife went mad and committed suicide.
The reason why the t is doubled in the -ed and -ing forms is that the stress falls on the final syllable of the verb in its infinitive form: commit.
The same rule applies to other verbs ending in ‘t’ where the stress falls on the final syllable:
When the stress does not fall on the final syllable, the -ed and -ing forms are spelled with one ‘t’:
Don’t spell commit with only one ‘m’:
✗ A crime is comitted because the perpetrators want to attract attention.
✓ A crime is committed because the perpetrators want to attract attention.