Elvyn Rodriguez was still fuming that his girlfriend had ended their relationship just before Christmas, and he became enraged when he saw her with another man, police said Tuesday.

So on Monday afternoon, Rodriguez, 32, drove to the Norristown apartment he once shared with Keishla Arroyo-Rodriguez, forced his way inside, and then killed her as her three children sat in a room nearby, detectives wrote in court filings.

On Tuesday night, the Montgomery County District Attorney’s Office said Rodriguez surrendered to police in York. He was expected to be arraigned Wednesday and then remanded to the Montgomery County Correctional Facility.

“This murder of Keishla Arroyo-Rodriguez, a mother of small children, is a horrific ending to a domestic violence situation,” District Attorney Kevin Steele said in a statement issued earlier Tuesday announcing that Rodriguez had been charged and was being sought.

On Monday, detectives were called to Arroyo-Rodriguez’s apartment on Main Street for reports of a woman shot and unresponsive, according to an affidavit of probable cause for Rodriguez’s arrest. Inside, the officers found Arroyo-Rodriguez dead, shot once in the head.

Her 7-year-old daughter, with help from an interpreter, told police Rodriguez had come into the apartment suddenly and confronted her mother in the bathroom, the affidavit said. The girl heard several loud bangs from inside the room as she sat nearby with her 3-year-old and 5-year-old siblings, before Rodriguez left the bathroom, locked the door behind him, and fled the scene by stealing Arroyo-Rodriguez’s car.

The 7-year-old called her father, saying “Elvyn came in the house and was hurting Mommy,” according to the affidavit. When her father arrived, he forced the bathroom door open and found Arroyo-Rodriguez on the floor.

In an interview with detectives, the girl’s father said Rodriguez had called him earlier Monday, acting in “a jealous manner” and asking him whether he had seen Arroyo-Rodriguez with another man, according to the affidavit.

The father told detectives that Arroyo-Rodriguez told him Rodriguez had hit her in the face and said she ended their relationship right before Christmas, the affidavit said.

Staff writer Robert Moran contributed to this article.