A well-known Kenyan businessman and outspoken critic of the government, Jacob Juma, was found dead in Nairobi last week, shot by unknown assailants and left in his car on a busy highway. Three days after his death, a new investigative unit has taken over the case but police have not yet established any suspects.

Various theories are circulating as to why Juma, who was involved in mining and real estate in Kenya, was targeted. (Theft appears unlikely since cash and his mobile phones remained in the car.) He has been a party to several lawsuits against members of the government, and was a vocal critic of Kenya’s inaugural international sovereign bond issue, which critics claim gave the government cover to steal almost $1 billion.

Police said there were no witnesses to the shooting, despite the fact that it took place on a busy Nairobi road, five minutes from a police station. Juma’s Mercedes was riddled with bullets but he appears to have been shot at close range as well, according to the police.

“The state is a suspect. Police cannot be trusted to to do a thorough investigation,” said Raila Oding, head of the opposition party that hopes to challenge president Uhuru Kenyatta in 2017. Odinga has called for foreign agencies like the FBI or Scotland Yard to manage the investigation, which is very unlikely.

Juma was prolific on Twitter, especially when it came to criticism of Kenyatta’s administration. Kenyans have taken to social media to comment on this fact, using the hashtag #safetweets to sarcastically praise the government and apologize for ever criticizing it.

On the morning of May 5th, the day he was found dead, Juma retweeted a quote by Pope Francis, “The Lord consoles us. We are all called to comfort our brothers and sisters, to testify that God alone can eliminate the causes of tragedies.”