A woman in Wisconsin who was pregnant with her second child was found dead this week after her estranged boyfriend allegedly set her family's house on fire with the 3-year-old child they share still inside, police said. Milwaukee police arrested a 21-year-old man in connection with the death of Gladys Johnson who was found dead in her home on the night of Monday, January 5, according to WISN. The suspect's name has not yet been publicly released since he has not yet been formally charged. Police said that the detained suspect was Johnson's estranged boyfriend. In addition to being the father of her 3-year-old daughter, the suspect was also the father of the unborn son she was pregnant with at the time of her death. Police said that the suspect does not have a criminal record in Wisconsin, according to the outlet. However, authorities did confirm that the couple had a history of domestic violence. Officers with the Milwaukee Police Department responded to the home where Johnson lived with her family around 11:30 p.m. on January 5. Man Accused of Murdering Pregnant Girlfriend, Setting Her Home on Fire Johnson's mother, Michelle Johnson, told local news outlets that she grew concerned when she smelled smoke inside the home. She told WITI that her daughter's boyfriend would not allow her into her daughter's bedroom and claimed he blocked the door while saying, "No, you [are] not getting in here." The boyfriend then allegedly pointed his gun at Michelle's other daughter before he fled the home. Michelle then managed to get into the room, where she was able to put out the fire and found her daughter unresponsive. "I found her, and I didn't want her to burn up. And God had my back. He still took her and her baby, but she's in heaven with my mom. And she's watching down on me," Michelle told WISN. "But now I have to stand up for her baby. I have to raise her with my other daughters." Michelle added, "He was wrong for taking my daughter's life." After the suspect fled the scene, officers arrested him less than a mile from the home about 30 minutes after the fire was reported to 911, according to Milwaukee Police arrest records. The Milwaukee County Medical Examiner ruled Johnson's cause of death as homicide, per WISN. Additionally, it was concluded that the victim "may have sustained traumatic injuries following an assault from her significant other." Wyoming Woman Predicted Ex-Boyfriend Would Kill Her Before Murder-Suicide "If she didn't want to be with you no more, she wanted to live her life. She was also carrying a baby," Johnson said of her late daughter. "And God should punish you for that. Now I'm going to miss my daughter and my grandchild that she was carrying. You should get punished the same way you punished her." Michelle also reflected on how her daughter's passing will impact her 3-year-old granddaughter. "It's going to be a hard time to tell her, a 3-year-old, that your mother was not only sleeping, but then she's going to see her in a casket," she said. The Milwaukee Police Department confirmed to Us Weekly that the case is currently under an active investgiation.