Criminal homicide charges were filed Monday against Michael Lindgren in the beating death of his 77-year-old mother, Shirley Lindgren, at her home in Bethlehem’s Central Historic District.

Lindgren was arraigned on the new charge before District Judge Roy Manwaring by videoconference from Northampton County Prison. Under Pennsylvania law, there is no bail for criminal homicide cases.

One of two charges of attempted homicide was dropped. Lindgren is also accused of severely beating his father, John Ralph Lindgren, who like his wife suffered severe head injuries during an attack that took place at their 209 E. Wall St. home.

Lindgren, 51, of 516 Hayes St., is also charged with two counts each of aggravated assault, simple assault and reckless endangerment.

Bethlehem police responded to a burglar alarm at the home a little after midnight on Aug. 21, when, according to court records, they found Michael Lindgren walking out of the house with his hands and shoes covered in blood.

Just inside the front door, police found Shirley Lindgren lying unconscious in a pool of blood. She died at St. Luke’s University Hospital the next day of “severe head injuries,” according to Lehigh County Coroner Scott Grim.

Services for Shirley Lindgren are planned at 9:30 a.m. Saturday at First Presbyterian Church, 2344 Center St.

According to an obituary published on the Long Funeral Home Website, Mr. and Mrs. Lindgren celebrated their 53^rd anniversary in December.

Born in Mesa, Ariz., Shirley Lindgren was the daughter of the late Merlin O. and Josephine (Haley) Tryon. She attended Brigham Young University and Lake Forest College in Chicago.

She was an executive secretary for Easter Seals, retiring in 1997. She served on the Bethlehem Area School District Board from 1981 to 1985. She was a founding member of the Bethlehem Special Olympics, serving on the board from 1976 to 2011 and in 2011 was inducted into the Pennsylvania Special Olympics Hall of Fame.

She was a member of the League of Women Voters, the Lehigh Women’s Club, the Bethlehem Garden Club, the Bethlehem Historic Neighborhood Association and the Parent Advisory Committee of BASD from 1975 to 1982.

In addition to her husband, she is survived by her daughter, Kathryn; three other sons, Thomas, David and Timothy; a brother, two sisters and six grandchildren.