Fotis Dulos’ defense team has hired high-profile private investigator Patrick McKenna, who has worked on the O.J. Simpson and Casey Anthony murder cases, to assist in their defense of Dulos, who faces charges in connection with the disappearance of his estranged wife, New Canaan mother Jennifer Farber Dulos.

Sources on Tuesday confirmed the move by the defense team, which is led by New Haven attorney Norm Pattis. Pattis declined to confirm the hiring but said, “We will spare no expense or effort in defense of Mr. Dulos.”

Reached by phone Tuesday, McKenna said he could not talk about his work. A LinkedIn profile lists his clients, including Anthony, Simpson and Yoko Ono. It is not uncommon for private investigators to assist lawyers with cases.

Dulos, 51, of Farmington, is free after posting $500,000 bail as investigators continue to probe the disappearance of Farber Dulos, 50, the mother of his five children. Farber Dulos and the children were living in New Canaan when she went missing on May 24. The couple is involved in a contentious two-year divorce.

Investigators said a man resembling Dulos was seen on surveillance videos discarding contractor bags with bloody items in trash cans along Albany Avenue in Hartford the night that Farber Dulos was reported missing. Police learned the items in the bag tested positive for Farber Dulos’ blood, court records show.

In a recent court hearing for Dulos, Stamford/Norwalk State’s Attorney Richard J. Colangelo Jr. said that Dulos’ DNA was found mixed with Farber Dulos’ blood in her New Canaan home.

A woman resembling Dulos’ girlfriend, Michelle Troconis, also was seen in the surveillance videos obtained by Hartford police and given to state police investigators, records show. Both Dulos and Troconis have pleaded not guilty to charges of evidence tampering and hindering prosecution.

Pattis has said he is pursuing a theory that Farber Dulos’ disappearance was a “revenge suicide.”

Dulos is scheduled to return to Superior Court in Stamford on Aug. 2. Troconis’ next court date is Thursday.