Her parents, both nurses, immigrated to San Jose from Sierra Leone shortly before she was born.

She gave up her final year of eligibility to compete in the NCAA after she went professional, signing with Nike.

On June 23, 2012, Tarmoh finished in a dead heat with Allyson Felix for third place in the 100m finals at the US Track and Field Olympic Trials.

After discussion, USATF officials decided that a runoff between the two sprinters would take place in the event that neither ceded her spot to the other.

[5] The event generated substantial criticism toward USATF officials for having insufficient procedures in place for breaking ties, as well as for forcing the runners to decide whether to participate in the eventual runoff.