John Lavir ("rival" spelt backwards) was the brother of Lola Lavir. He was a slender man with light hair and a thin moustache.
John arrived at the Nuremoh family home after the death of Lola and Edward Nuremoh. He attempted to kill Tess Trueheart by ramming his car into hers. Tess, who was confused and estranged from Dick Tracy at the time, was enchanted by John and decided against pressing charges.
Tess went along with John and invested in his business of stealing dogs and reselling them. She soon began to feel guilty and started to return the dogs without John's knowledge. He found out and tried to get his dog with steel fangs to attack her. The dog turned on John and ripped out his throat. Tess was held briefly on murder charges but was eventually released.