One day after UnitedHealthcare CEO Brian Thompson was shot to death on a Manhattan street, two homes owned by his family close to each other in Maple Grove were the targets of a bomb threat police said were an act of "swatting."

Police said they received a report of the threat around 7 p.m. Wednesday supposedly targeting the residences that are about a half-mile apart. Police incident reports said the threat was expressed in an email to multiple people, who in turn alerted law enforcement.

One home is owned by Thompson and the other by his wife, Paulette Thompson, according to Hennepin County property records.

"No devices or suspicious items were located during the investigation," according to a statement from police . "The case is considered an active investigation, while the incident appears to be a hoax."

Swatting is an act of falsely reporting an emergency with the intent of sending police to someone's home. As of Aug. 1, swatting in Minnesota was escalated from a gross misdemeanor to a felony.

Public officials across the country have been targeted in swatting incidents, as have judges overseeing cases against President-elect Donald Trump. In January, someone tried to draw police and a hostage negotiator to the Delano home of Minnesota Republican U.S. Rep. Tom Emmer by claiming a killing had taken place there.

Maple Grove police said it was assisted in its investigation by the Minneapolis Police Department bomb squad and the Hennepin County Sheriff's Office.

In New York on Thursday, police released a photo showing the face of a "person of interest" in the fatal ambush of the executive as he walked on Wednesday morning to a hotel for an investors conference.

Police reiterated they believe Thompson, 50, was the victim of a premeditated and targeted attack. The suspect has yet to be located.