In a YouTube video posted last Thursday, Noah Harpham questioned what he called his father's involvement with the Revd Bill Johnson and the Bethel Church in Redding, California.
Benjamin Broadbent, lead minister of the First Congregational Church of Colorado Springs, released a statement he said was provided by Harpham's family, saying they were shocked and saddened and requested privacy.
Harpham, who was 33 was a recovering alcoholic, killed a cyclist in broad daylight on Saturday.
He then gunned down two women outside an addiction recovery centre and was killed following a gun battle with police.
His mother Heather Kopp, a writer in New York, described his long-time struggle with addiction in a book called Sober Mercies: How Love Caught Up With A Christian Drunk.
His mother's book describes him as "introverted and moody" and documents him turning to drugs and alcohol when he gave up on college.
The victims have been named as Andrew Myers, 35, Jennifer Vasquez, 42, and Christina Baccus-Gallela, 34.