Photo / Detroit Free Press

Patrick Mikes Jr. makes his way into court for the theft of his brother Andrew's credit card during his arraignment at 52-3 District Court in Rochester Hills, Mich., Wednesday, Aug 1, 2012. / ANDRE J. JACKSON/ Detroit Free Press (August 3, 2012)

TROY, Mich. – Police say an active search is underway in Montrose, Mich. for the body of a missing Notre Dame alum, and his son, also a Notre Dame student, may have been involved.

Cadaver dogs were being used.

Police believe 55-year-old Patrick Mikes, Sr. was killed in the basement of his family’s home where they found evidence of what’s being described as a “violent encounter.”

Police are calling his son, Patrick Mikes Jr., a suspect in his father's murder.

Investigators say they have surveillance video of the Notre Dame student buying cleaning supplies at a local store Friday evening.

Mikes Jr. was arrested and jailed on separate charges of credit card fraud, but bond was posted and he was released Thursday.

Mikes Jr. reported his father missing late Sunday morning and claimed he last saw him late Friday afternoon leaving for a ride on his bicycle.

Police say Patrick Mikes, Sr. was an avid bicyclist who never would have gone for a ride without his helmet. They found the helmet in the garage and his special biking shoes were found in the house.

Mikes' black and red Cannondale Super 6 road bicycle has not been found.

A source close to the investigation says carpeting in the basement of the home had been cleaned but was still "bloodstained."

The source also added that investigators are leaning toward money as a possible motive and that the father may have "cut Junior off financially."

Investigators have also seized two vehicles from the Mikes' house on Homewood Street.

Earlier this week, Mikes Jr. was taken into police custody as a suspect in his father's reported disappearance. He's now been charged with credit card fraud for allegedly stealing money from his 16-year-old brother Andrew.

Police say after being questioned, Andrew realized that the last time he saw his father alive was Thursday evening. Mikes never showed up for work on Friday.

The investigation is ongoing.