A 21-year-old man has been charged with second-degree murder after allegedly shooting dead his fiancée at their Minnesota home on  Easter morning while holding their baby daughter in his arms. Dimitri Harrell reportedly pulled out his gun and pointed it at 19-year-old Samirria White after they started arguing over his 'infidelity' in the bedroom of their St Paul apartment at around 3.40am. Carrying the couple's three-month-old child, he then shot Miss White in the face at close range, according to police. When medics arrived at the scene, they pronounced the young mother dead. Now, Harrell, who later admitted to having stored his handgun under his daughter's mattress, has been charged with one count of second-degree murder at Ramsey County District Court. Shooting: Dimitri Harrell (right) has been arrested after allegedly shooting dead his fiancée, Samirria White (left), at their Minnesota home on Easter morning while holding their baby daughter (center) in his arms . The suspect, who had  'trust issues' with Miss White after having two children by another woman, remains in custody in lieu of $200,000 bail. If convicted, he faces up to 40 years in prison. In the moments before Sunday's shooting, Harris had been arguing with Miss White after he had vanished from the apartment several times during the night, arousing her suspicions, relatives said. During an interview with police, the suspect apparently told officers he had then tried to pull his gun - which he had bought several days earlier - from his pocket while holding the couple's baby daughter. However, the weapon had accidentally discharged, he said, causing a bullet to strike Miss White in the face, according to the Star Tribune. It is unclear whether he explained why he took out the gun. Tragic: Harrell reportedly pulled out his gun and fired at 19-year-old Miss White (pictured with their daughter) after they started arguing over his 'infidelity' in the bedroom of their St Paul apartment at around 3.40am . Arrest: Now, Harrell has been charged with one count of second-degree murder at Ramsey County District Court. Above, the suspect is pictured in his mug shot (left) and posing with Miss White and their baby (right) Several people - including some of the victim's siblings - were also in the property at the time of the alleged murder. Many of them heard yelling come from the couple's bedroom, CBS reported. Miss White's 16-year-old brother, who woke up after apparently hearing his sister scream 'Don't point that gun at me!',  ran into the room when he heard the gunshot. There, he found his sister dead . The boy yelled at Harrell to get away from Miss White, according to a complaint obtained by the Tribune. In response, the suspect apparently told him it was an accident and fled the scene. After emergency crews arrived at the scene, Miss White was declared dead and the bedroom was cordoned off. Police later found the gun on Harrell's 'close friend', who was in the apartment. Scene: The shooting occurred in the 800 block of Pierce Butler Route (pictured) in Minnesota on Sunday . Family: In the moments before Sunday's shooting, Harris had been arguing with Miss White after he had vanished from the apartment several times during the night, arousing her suspicions, relatives said . The man, who has not been identified by officials, had reportedly received the weapon from Harrell just minutes after the shooting. The suspect had apparently told him: 'Do something with this'. Harrell, who is pictured with Miss White and their daughter in numerous Facebook photos,  told police that their relationship had been rocky since the births of his  two children by a different woman. On Tuesday, relatives described Miss White, a former Humboldt Senior High School student, as a 'spontaneous' and loving woman who had hoped to become a nurse and adored her daughter. On her Facebook page, Miss White lists the date she got engaged as March 23, 2012. She also reveals that she was born in Elgin, Illinois. Her three-month-old daughter's name is unknown.. Pregnancy: On Tuesday, relatives described Miss White (left, pregnant with Harrell and right, in another pregnancy shot) as a 'spontaneous' woman who had hoped to become a nurse and adored her daughter .
Dimitri Harrell, 21, was arguing with Samirria White, 19, over his 'infidelity'
With three-month-old daughter in his arms, he apparently pulled out a gun .
He then shot his fiancée in the face at close range, killing her, officials said .
Now, Harrell has been charged with single count of second-degree murder .
He revealed to police he had stored the gun under his daughter's mattress .
Also claimed he shot victim accidentally while pulling weapon from pocket .
Harrell caused 'trust issues' after having two children with another woman .
In custody on $200,000 bail; if convicted, faces up to 40 years behind bars .