Deputies said the boy screamed for his parents after a stranger entered the family’s apartment before dawn.
MIAMI-DADE COUNTY, FL — A 37-year-old man was arrested Thursday after deputies said he entered a northwest Miami-Dade apartment before dawn and sexually assaulted a sleeping 13-year-old boy inside the family’s home.
Karl Heinz Mercier, of northeast Miami-Dade, was taken into custody by the Miami-Dade Sheriff’s Office after the boy’s parents confronted him as he tried to leave the apartment, according to an arrest report. The case centers on an alleged 4 a.m. break-in at Park Towers, an apartment complex on Northwest 155th Lane near Northwest Seventh Avenue.
The arrest report said Mercier entered the apartment without permission while the family was asleep. Deputies said he went to the boy’s bed, lay next to him and touched him inappropriately while the child slept. The boy woke up and screamed for his parents, who were sleeping in another room. Deputies said Mercier told the boy, “Nothing is going to happen. No one is going to come.” The scream brought the parents into the room, where they found Mercier and confronted him as he tried to flee, according to the report.
The boy’s parents told deputies they did not know Mercier and had not invited him into their home. Responding deputies detained him after the parents stopped him from leaving, the report said. Investigators said Mercier admitted he had entered the apartment without permission and had touched the boy. Authorities have not said how Mercier got into the unit or whether there were signs of forced entry. No injury details beyond the alleged sexual contact were released in the reports available Friday.
Park Towers sits in northwest Miami-Dade, near a busy stretch of Northwest Seventh Avenue and close to Miami Gardens. The reported break-in happened while the family was home, a factor that shaped the burglary charge filed in the case. Under Florida law, burglary involves entering or remaining in a dwelling, structure or conveyance with intent to commit a crime when the person is not invited or allowed to be there. A burglary charge becomes more serious when an assault or battery is alleged during the entry or while the person remains inside.
Mercier was arrested on charges including burglary with assault or battery and attempted sexual battery on a minor, according to jail and police information cited by local reports. WSVN reported that Mercier appeared before a judge Friday and was ordered to stay away from the victim. The station also reported that no bond was given on both charges and that Mercier remained behind bars. Earlier jail records cited Friday morning listed his bond as still to be set.
The case moved quickly from the apartment to jail after the family’s confrontation and the deputies’ response. The arrest report placed the incident at about 4 a.m. Thursday, with the arrest following soon after. By Friday, Mercier had been booked into the Turner Guilford Knight Correctional Center, the main Miami-Dade jail complex used for many felony defendants after arrest. Court records and future hearings are expected to determine whether prosecutors file formal charges and whether any bond conditions change.
The allegations rely in part on the boy’s account, the parents’ statements and Mercier’s reported admission to deputies. Officials have not released the child’s name, and local reports did not identify the parents. The report said the boy’s immediate scream alerted the adults in the apartment, making the parents the first people to confront the suspect before deputies arrived. Investigators have not released further details about surveillance video, door locks, witness accounts from neighbors or any prior link between Mercier and the apartment complex.
As of Saturday, May 2, Mercier remained accused but not convicted in the case. The next key step is the filing process and any upcoming bond or arraignment hearing in Miami-Dade criminal court.
Author note: Last updated May 2, 2026.