The discovery was made Wednesday evening in the parking lot of a TD Bank in the Hillcrest area.
Authorities say 25-year-old Eric Maleh was riding the motorcycle on Utopia Parkway in Hillcrest Sunday night when he swerved around a car and lost control, slamming into a house.
Police say the two were talking when the man pushed the woman's cane out of the way, reaching into her pocket and stealing her wallet.
The trio vanished after the eldest sibling took her 2-year-old sister and 6-year-old brother for a walk near their home in Hillcrest.
Police say the 21-year-old victim, a college student from Pakistan, was near 165th Street and 81st Avenue in Hillside when a black van rolled up to him just after 4:30 p.m.
The flames broke out on the second floor of a home on Stark Court in Hillcrest just after 8:30 a.m. and quickly spread through the roof.