New details have emerged in the investigation into the murder of UnitedHealthcare CEO Brian Thompson. A San Francisco police source revealed to Fox News that an investigator recognized Luigi Mangione, the accused shooter, from a missing person poster circulated by the police department. This recognition occurred while Mangione was still at large and was communicated to the FBI.

The poster, which Fox News obtained, features a picture of Mangione and indicates that he was reported missing on November 18, 2024, approximately two weeks before Thompson's death. According to the police source, Mangione's mother filed the missing person report, stating she last contacted him around July 1 and believed he worked at True Car. The provided work address and lack of contact information hindered the initial search.

The San Francisco Chronicle, citing sources familiar with the investigation, reported that police identified Mangione four days before his arrest in Altoona, Pennsylvania. At the time of his arrest, authorities stated Mangione had no prior criminal record. An FBI source confirmed receiving a tip from the San Francisco Police Department regarding Mangione's potential involvement in the December 4th shooting. This information proved crucial in the subsequent investigation and apprehension of the 26-year-old Ivy League graduate.

Mangione is currently facing charges in Pennsylvania for forgery and carrying an unlicensed firearm. He has yet to waive his right to an extradition hearing for the murder charges in New York, though Manhattan District Attorney Alvin Bragg indicated there are signs he may do so. Currently held without bail, Mangione awaits a potential habeas corpus filing by his attorney.

Authorities believe Mangione ambushed Thompson outside the hotel hosting UnitedHealthcare's annual investor conference. CCTV footage captured the incident. During his escort into a Pennsylvania courthouse, Mangione verbally challenged his arrest, expressing sentiments deemed out of touch with public perception. He appeared composed during the hearing, conferring with his attorney.

Investigations reveal Mangione was not a UnitedHealthcare client, nor was his mother. NYPD Chief of Detectives Joseph Kenny suggested Mangione might have targeted the company due to its prominent position within the healthcare industry. A note found on Mangione referenced UnitedHealthcare's ranking as the fifth-largest corporation in the US. Kenny also disclosed Mangione's significant back injury in July 2023, a life-altering event that investigators are exploring as a potential factor in his actions.