Details of Disappearance
Derewitz ended her relationship with her fiance, David Kniga, in May 2001. Derewitz moved out of the home they shared in Dearborn Heights, Michigan at that time. She arrived at her Kniga's residence in the 3900 block of Detroit Street near Colgate Street to exchange mail on June 3, 2001.
Kniga's new girlfriend was also visiting the house and told authorities that Derewitz and Kniga had an argument. Derewitz apparently left the residence, then returned shortly thereafter. She had a confrontation with his new girlfriend at that time. The girlfriend stated that Kniga grabbed Derewitz and went into the basement with her. He came upstairs and told his new girlfriend to leave shortly afterwards. The girlfriend told authorities that she saw Derewitz laying on the basement floor as she departed the residence. Derewitz was gasping for breath and appeared to be severely injured. The girlfriend did not summon authorities or call for medical assistance as she left the house. She was last seen wearing a gray shirt, reddish-colored boxer shorts and house slippers. Derewitz's 1994 or 1995 teal green Ford Escort was discovered abandoned in the parking lot of Ten Eyck Park on June 7, 2001, four days after her disappearance. It had apparently been parked there on June 5 or 6.
The new girlfriend has cooperated with authorities and has taken a polygraph exam regarding Derewitz's case. Kniga was scheduled to take a lie detector test, but he hired an attorney instead. He has maintained his innocence in Derewitz's disappearance and claimed that his new girlfriend and Derewitz were at his home on June 3, but they arrived at different times.
In June 2003,police charged Kniga with second-degree murder in her case. At the time of his arrest Kniga was still living in the home he used to share with Derewitz. He originally pleaded not guilty to the charge, but in October 2003 changed his plea to guilty of manslaughter to avoid a life sentence in prison. Kniga was sentenced to five to fifteen years in prison. Derewitz's body has yet to be found.

Investigating Agency
If you have any information concerning this case, please contact:
Dearborn Heights Police Department
313-277-7468
OR
313-277-6770

Source Information
Amy's Missing