Lempaa is an Advocate of the High Court of Kenya. His Academic Achievements include a masters degree in International Human Rights Law from the University of Essex(2011), an LLB of the University of London(2007), PostGraduate Diploma in Mass Communications, University of Nairobi(2001) and a BEd Arts Kenyatta University (1999). He has in the past worked as a High School teacher, a Journalist of the High Court of Kenya and lecturer Media Law and Ethics at Jomo Kenyatta University of Science and Technology. Lempaa has been a leading public interest litigator and advocate. Apart from being multidisciplinary, Lempaa is also multilingual with a working experience in five languages. He has been involved in the high profile public litigation cases. He is an an Alumni of four universities despite a beneficiary of Ford Foundation fellowship in 2010, 2011 programme.