Homicides more than doubled in Lafayette in 2015, a year that saw a rise in street killings, a significant increase in unsolved slayings and the killings of two people in a shooting rampage at The Grand 16 Theatre.

Although overall reported crimes are down 2 percent, including robberies, burglaries and assaults, city police investigated 20 homicides last year, up from nine in 2014, according to Uniform Crime Reporting statistics submitted to the FBI and released Tuesday by the Lafayette Police Department. There were 10 homicides in 2013 and 12 in 2012.

From his office on Tuesday, interim Lafayette Police Chief Reggie Thomas called the numbers “totally unacceptable.”

Thomas, who oversaw a majority of the homicide investigations as Precinct 4 supervisor before he replaced retired Chief Jim Craft this month, said more of “the wrong people” are carrying weapons.

“It’s not gang-related or anything like that,” Thomas said. “I always tell people it’s almost like sometimes kids watch rap videos and think they want to carry a gun. And a kid with a gun who doesn’t understand anything, that’s when we have problems.”

The increases happened elsewhere in the state, with at least 78 people killed in Baton Rouge in 2015 — an increase of 15 killings after two years of declines. New Orleans also saw its first increase in slayings since 2011, with 10 percent more homicides — or 165 killings — investigated since last year.

The homicides in Lafayette include 14 shooting deaths in neighborhoods north of the Evangeline Thruway, including an accidental shooting that killed one of two 18-year-old Northside High School seniors playing with a gun.

Five of the 14 killings remain unsolved, prompting Thomas to begin a task force that will focus exclusively on those cases, as well as an unsolved November 2014 shooting death on West Gilman Road — the only killing that year that didn’t lead to an arrest.

A sergeant and three investigators appointed to the force will give fresh eyes to the killings in an effort to cull evidence needed to make arrests.

“Every investigator sees things differently. So I’m confident once they look at these cases, they will get new evidence and they will start attempting to solve some of them,” Thomas said.

The homicide numbers include the two women killed in the Grand 16 Theatre shooting, when an Alabama gunman opened fire during a film and injured nine other people before turning the gun on himself.

Another two people, including a 17-year-old, were shot and killed outside an apartment complex on Merchants Boulevard off Pinhook Road, and a man shot and killed another man during an argument outside a Johnston Street McDonald’s. Investigators deemed one killing justified after a woman shot and killed a man who attacked her outside a bar on Pinhook Road.

Police also investigated as a homicide the discovery of a premature newborn’s corpse found in a box in its mother’s storage unit 14 years after the infant’s death.

Five of those killed in Lafayette were between 17 and 19 years old; eight were between the ages of 21 and 33; and six were between the ages of 44 and 64.

Reported forcible rapes nearly doubled, at 19 in 2015 compared with 10 the year before — although the number has shown up and down fluctuations over the years. There were 17 reported rapes in 2013 and 11 in 2012.

The number of juvenile arrests has continued a downward trend, decreasing each year from 1,177 in 2012 to 766 in 2015 — about a 35 percent decrease during that time.

Thomas attributed the ongoing decrease to the Juvenile Assessment Center operated by the Lafayette Parish Sheriff’s Office, where juvenile offenders are taken instead of jail and evaluated for potential social services.

“A lot of these programs really work,” Thomas said.

Adult arrests in 2015, however, increased by 9 percent to 11,919.

Assaults decreased by 6 percent, burglaries by 15 percent and robberies by 32 percent. Thefts increased by 2 percent.

Thomas also brought attention to the number of calls for service made in 2015, which decreased by about 12,000 — or 5 percent — to 226,805.

“I also want the community to know we need them. Without them, we can’t solve these cases,” Thomas said.

Follow Lanie Lee Cook on Twitter, @lanieleecook, or contact her by phone at (337) 534-0825.