Three MPs have lost their seats after their victories in last year's elections were nullified.
Alfred Keter (Nandi Hills), Chris Karan (Ugenya), and Wanjiku Kibe (Gatundu North) will have to go back to the drawing board after courts overturned their elections.
However, it was good news for Narok Senator Ledama ole Kina and MPs Caleb Amisi (Saboti), Mark Lomunokol (Kacheliba), and George Sunguya (Kajiado West), whose wins were upheld.
Karan's win had been challenged by former MP David Ochieng. He suffered a further blow after the court ordered him to pay Sh3.5 million in costs.
Two other respondents, including the Independent Electoral and Boundaries Commission (IEBC), will cost-share another Sh3.5 million in costs.
Justice Thrispisa Cherere ruled that Karan’s election was marred by irregularities that started during the campaigns to the Election Day.
The court said Karan and the ODM fraternity engaged in a smear campaign against Ochieng and the Movement for Democracy and Growth party.
Ochieng based his petition on four grounds, including being associated with the death of former IEBC manager Chris Msando.
Msando hailed from Ugenya and his brutal murder elicited strong emotions across the country.
Ochieng said by linking him to Msando's death, Karan made the environment hostile for him to campaign.
Justice Cherere said Ochieng convinced the court intense propaganda made it difficult for him to campaign, casting doubts on the results declared.
Karan said he would appeal the decision.
Residents of Gatundu North constituency in Kiambu County will also head back to the ballot after the nullification of Ms Kibe's win.
Former MP Kung’u Waibara challenged the win on grounds the election was not free and fair.
Waibara garnered 9,390 votes against Kibe’s 39,447.
High Court judge Joel Ngugi said the election was marred with irregularities and illegalities that affected the results.
Justice Ngugi said the court relied on an independent analysis of 125 forms 35A, out of the 126 produced in court, to arrive at its decision. Nullification of Kibe's win was also informed by a report on the scrutiny of ballot boxes from 29 polling stations.
He said analysis of forms 35A showed that 26 had no IEBC standard mark, as required by the law.
The judge said the analysis also revealed unauthenticated alteration of results in four polling stations. Some forms 35A did not have the signatures of the presiding officers and their deputies. At least 103 ballot papers were missing.
He ordered IEBC to conduct a fresh election in the area in strict conformity with the law. He also directed the electoral body to pay Kibe Sh3 million after the court found she had not committed any offence. The IEBC will also pay the petitioner Sh1.5 million.
The judge also ordered the investigation of six people to establish if they committed any offence. These include presiding the officers at the Mutuma, Ndeki, and Mungai polling stations and constituency returning officer Patrick Muthee. Also recommended for investigation were the constituency logistics officer, Patrick Ndung’u, the county logistic officer, Thomas Waweru, and the petitioner.
Kibe was the only woman elected to Parliament in the 12 constituencies of Kiambu County.
In Naivasha, a court ordered that IEBC officials in Narok County be investigated for alleged criminal activities during the senatorial elections.
Justice Christine Meoli ruled that some of the officers tampered with crucial documents during tallying of votes and declaration of results.
She, however, exonerated the candidates and voters from blame as she dismissed the petition against ODM's Senator Ledama ole Kina.
The petition was filed by Jubilee's Nkoida ole Lankas and Andrew Kiplagat of the National Vision Party.
Meoli ordered the petitioners to pay Sh2 million as costs of the suit, half of which will be footed by IEBC.
The supporters of Kajiado West MP George Sunguya could not hold back tears of joy after a petition challenging his win was dismissed. Court proceedings were temporarily disrupted as police tried to control them.
The MP, who is a former speaker of the Kajiado County assembly, survived an attempt to invalidate his win when Justice John Onyiengo dismissed the petition by Joseph ole Simel.
Justice Onyiengo said the petitioner failed to prove the election was marred by illegalities and that votes were inflated in Sunguya's favour.
Onyiengo said Simel did not present evidence to show some polling stations had more votes cast than registered voters. The petitioner will pay Sh1 million as costs of the case.
In Kitale, Justice Cecilia Githua upheld the election of Caleb Amisi of Saboti. She dismissed a petition by Jones Kuko, citing his failure to prove allegations that the election was not conducted according to the law.
She said witnesses for the petitioner were untruthful and unreliable as they provided contradicting evidence.
Justice Githua said IEBC conducted the elections in a free and fair manner, and according to the law. Kuko will pay Sh4 million. Mr Amisi and IEBC will share the money.
Amisi and his lawyer, Anthony Olouch, who is also the MP for Mathare, lauded the judgement, saying it demonstrated the will of the people.
Kacheliba MP Mark Lomunokol's re-election was validated by Kapenguria-based judge Stephen Githinji. The petitioner, John Lodinyo, was ordered to pay Sh2.5 million as costs of the suit.
“I have observed 13 grounds on this petition and come to the conclusion the petitioner failed to present credible evidence to prove his claim the election was marred with malpractices," said Githinji.