The chief of presidential security under former Haitian President Jean-Bertrand Aristide was shot to death Monday in the capital, where he had lived since returning to the country after finishing a prison sentence in the United States.

Oriel Jean, who had received a reduced sentence because he provided substantial assistance to U.S. authorities investigating allegations of drug trafficking tied to the Aristide government, was killed in an apparent ambush in the Delmas district of Port-au-Prince, police said.

National Police spokesman Gary Desrosiers said two men on a motorcycle came up to Jean and one opened fire before they fled into the crowded streets. The former official was struck in the neck and stomach. No suspects were in custody.

After the attack, as officials tried to collect evidence and witness testimony, Jean's body was sprawled on the street as if he had been shot just as he stepped out of the vehicle, a grey Toyota SUV with tinted windows. The street, in a busy commercial and residential district, was packed with people heading home in the late afternoon.

Jean, who was about 50, had returned to Haiti after completing a sentence in the U.S. for money laundering.

From 2001 to 2003, he had been the head of security for Aristide, who was forced from power in a violent rebellion in February 2004. The following month, Jean was arrested in Canada and extradited to the United States to face charges stemming from an investigation focused on officials and associates of the former government.

Jean had faced up to 20 years in prison but was sentenced in Miami to only three years after providing what officials described in court documents as "substantial assistance" with other cases. The three-year investigation resulted in the arrests of 14 Haitians who held top government and private jobs during the Aristide administration.

He testified in one case that an accused Haitian drug kingpin received a security badge, at a cost of $40,000, which enabled him to travel freely about the country without Haitian police searching him at a time when the Caribbean country had become a transit point for cocaine bound for the United States. Jean testified that the badge had been approved by Aristide but said that the then-president was unaware at the time that his security chief was involved in the drug trade.

Aristide, a former priest who became the first democratically elected president of Haiti, was forced out by a violent rebellion in February 2004. He returned from exile in March 2011 and has kept a low profile though he has been under investigation for corruption while in office.

As a potential witness in that case, Jean had been ordered not to leave the country, Desrosiers said.