It's typical for the number of shootings in the city to rise along with the temperature, police say.

But this hasn't been a typical year.

"This winter didn't slow down," said Columbus police Detective Ron Lemmon, with the third-shift assault squad.

As of Thursday, there were 42 homicides in the city — a 44 percent increase compared to the same time last year, when there were 29 homicides.

It's unclear what's causing the rise.

One reason could be that police have investigated six double homicides already this year. During all of last year, there was one triple homicide and three doubles.

The relationships between those killed in double homicides this year have included best friends, brothers and a couple.

It's unclear whether there have been more shootings overall this year. Investigators say it feels like there's been a jump, but that's not something Columbus police track. In the assault unit, felonious assaults — stabbings, shootings, etc. — warrant the same charge.

"It's something people might want to know, but it doesn't benefit us as a law-enforcement agency," said Sgt. James Jardine, who oversees the second-shift assault unit.

He said that regardless of the number of non-fatal shootings, detectives still investigate every case.

Sgt. Jeff Strayer, who oversees the third-shift homicide squad, said the numbers could be even higher. There have been a number of shootings in which there were multiple injuries but only one fatality.

On March 11, there was a shooting at a sweet 16 party that left two wounded and one dead. It could have been a double fatality had a police officer not used a tourniquet on one of the victims, Strayer said.

Experts say it comes down to where and what kind of wound patients suffer, and whether they reach surgeons within the "golden hour" — the optimal time frame to save trauma patients.

"Two inches and a squad ride," Strayer said. "It's a roll of the dice."

A coordinated trauma system and quick response in Columbus means gunshot injuries don't have to be fatal.

How quick? Dr. Michael Shay O’Mara, who oversees trauma and acute-care surgery for OhioHealth, recalled a recent case.

"From the time the Columbus fire department was called to the time I was in the operating room was 12 minutes," he said. "That's ridiculously fast. ... We know with gunshot wounds, every minute matters."

This month, OhioHealth Grant Medical Center opened a third trauma bay. O'Mara said it's being used. "It's been parallel to what police are seeing," he said.

About one-fourth of the homicides this year occurred on the Hilltop. The South Side was close behind.

Other cities also have noticed upticks in violence.

Last year, Indianapolis set a record year with 149 homicides. As of April 21, 33 homicides had occurred there, according to police.

"I’m not sure why Indianapolis, like many other cities, is seeing such an increase in violent crime," said officer Nicholas Ragsdale, a spokesman for the city police department.

The force "has focused on increasing patrol in 'hotspots,' we’ve increased staffing in our investigative units and we’ve decentralized our narcotics units and put them back in the districts."

In Baltimore, 103 people had been killed as of Thursday. For all of 2016, there were 316 homicides, according to the Baltimore Sun.

Chicago saw a sharp spike in 2016. According to the Chicago Tribune, there were 786 all of last year. As of Thursday, there have been 184 homicides, compared to 192 through April 2016.

In Columbus on Thursday, 20-year-old Tyquan Hawkins-Scruggs was shot inside a South Side residence. He was pronounced dead within an hour at Grant Medical Center.

At the scene that afternoon, Sgt. David Sicilian said the increase in homicides so far this year is noticeable.

"I have no real explanation or evidence as to why," said Sicilian, who oversees the first-shift homicide unit. "We're following the trend in the nation. We don't want to follow that trend."

bburger@dispatch.com

@ByBethBurger