A Baton Rouge police detective testified Wednesday that he believes Instagram messages between two teens about a gun sale led to a December fatal shooting, implicating a 17-year-old in the killing of a 19-year-old. 

Based on that testimony at detention hearing Wednesday, Juvenile Court Judge Adam Haney ruled that prosecutors have enough evidence to move forward with the case against the 17-year-old arrested last month in the killing of 19-year-old Charvon Johnson. 

BRPD Detective Jeffrey Anders testified that investigators believe the 17-year-old fatally shot Johnson on Dec. 4 behind an abandoned house on Jackson Avenue, just off North Acadian Thruway. Anders said the two teens had messaged on Instagram about Johnson selling the 17-year-old a handgun, leading to their meetup that day. The 17-year-old messaged from an account that matched his name, and includes photos of him. Johnson messaged from a friend's account, Anders said.

About 5:30 p.m., the two teens were dropped off by separate vehicles, and met behind the abandoned home.  

While Anders said there were no witnesses to the shooting and a gun was not recovered, a number of neighbors heard gunfire. Johnson later died of multiple gunshot wounds. The person who dropped Johnson off for the transaction gave identifying features, including tattoos, of the person Johnson met behind the house; Anders said that description matched the 17-year-old. 

Anders said detectives also found multiple 9 mm shell casings on a back patio of the abandoned house. He said ballistics testing matched those shell casings to the ones found at a prior armed robbery for which the 17-year-old has also been implicated. 

Anders said police interviewed the 17-year-old, but he denied any involvement in the shooting. 

The 17-year-old was 16 at the time of the fatal shooting in December, which is why the case was heard Wednesday juvenile court. The Advocate typically does not identify juveniles until they have been charged in adult court. 

While the court found probable cause to move forward in the case, which automatically transfers further proceedings to adult court, the 17-year-old has not been charged in the homicide. However, he has already been charged as an adult in the prior armed robbery case, which occurred two days earlier, on Dec. 2. 

In that case, Assistant District Attorney Courtney Myers requested a judge transfer the 17-year-old out of the local juvenile detention center and into an adult jail, which was granted, sending him to the custody of the East Baton Rouge Sheriff's Office in late January. However, Parish Prison no longer has appropriate detention facilities for juveniles, which under federal law includes any defendant younger than 18. 

The Sheriff's Office instead contracts with a jail in East Carroll Parish, more than three hours north of Baton Rouge, to house any juvenile defendants, a change that has prompted a recent flurry of concern and litigation by youth advocates.

Two Baton Rouge attorneys last month argued that having no local detention spot for juveniles charged as adults inhibits the youths' legal representation, as well as their access to educational opportunities and family visits. Two of their clients, both juveniles charged with murder, have been ordered back to the juvenile detention center for detention as they await trial, however, one only until a further hearing. 

The 17-year-old accused in this case sat in court on Wednesday in a black-and-white jumpsuit that read RBDC on the back, for Riverbend Detention Center, the East Carroll Parish jail. His mother sat with him, as well as his attorney, A. Hays Town III. The teen hugged a younger family member as they left the courtroom. 

Town said that if he remains on the teen's case — the teen's family indicated they plan to hire an attorney — he may also file to have the teen returned to the juvenile detention center in East Baton Rouge Parish. 

“It’s the appropriate facility for him and it makes mine, or the attorney’s, job easier," Town said after the hearing. He declined to discuss more about either the armed robbery or the homicide. 

Haney set the 17-year-old's bail at $200,000 for a count of second-degree murder. Haney also found probable cause for a count of illegal possession of a handgun by a juvenile.

Follow Grace Toohey on Twitter, @grace_2e.