Also killed were 88-year-old Alice Hurst and her son. Darrel Hurst, 63, had been visiting his mother, and police have said they may have been returning from the grocery store.
Choucroun and the Hursts were found dead on the scene. The Taylors died of their injuries a week later.
Hours after the south Kansas City attacks, officers were called to a suburban motel where three people reported being attacked.
Howell was arrested walking along the freeway carrying a shotgun in his pants.
Two of the three victims from the motel identified Howell as the attacker.
Besides the murder counts, Howell is charged with four counts of armed criminal action, first-degree burglary, stealing a motor vehicle and unlawful possession of firearm.
After Monday's hearing, prosecutors took a group of Taylor's relatives and neighbors to a private room and a court employee said they declined comment.
Kansas court records show that Howell pleaded guilty in 2000 to a 1999 home invasion in Johnson County, Kansas. He was sentenced to 12 years but was paroled in 2011.
He also was acquitted in 2009 in the killings of two Kansas teenagers who were last seen in 1998. One victim's body was later found buried outside a Kansas City home being renovated by Howell's father; the other body has never been found.
Howell is being held without bond and his next court appearance was scheduled for Dec. 11.